I understand the movement for Impa. This is kind of a pick I've always been a bit stubbornly opposed to putting too much stock in, since it has always read to me as something of a desperation to find the "sensible" option. Again, I get it, but I don't know if any of Impa's singular appearances are demanding her to be playable over even those one or two shot characters who have left more of a prominent, lasting impression. Sidon is a choice that I'm really not all that confident in, I'm just kind of spitballing with Switch-era Zelda picks, but Impa is the kind of character I'm really just gonna have to see to believe.
No worries. Like I said, I don't have any real stake in the Zelda series proper and I'm certainly not going to lose much sleep over who gets picked, the more important matter is if anyone new gets added at all. It would be much easier to name a character if there was a single one consistently being rallied, but the split nature of everything regarding the series does kind of force me to stick to the "safe" option in my gut.
Octolings will be playable, 100%. I'm just not convinced they will be fully original characters, so I left them off of this list on the assumption they will be clones. My dark horse scenario is just that Splatoon is a series that can easily justify two new faces after such tremendous growth, and Smash Ultimate pretty much just accounting for Splatoon 1 for the most part. Contrary to Animal Crossing, it is also a series that specializes in diverse combat. So yeah even though it could get by with two characters, I'm going out on a limb and advocating for it to get just a little more than what's "safe" to assume.
As for the idols themselves, when we're thinking about some of the most popular new faces to come out of the last decade then they ought to be in the conversation. Off the Hook is demonstrably the most popular of the three as well, and IMO just offer the best material. I think this is a very prominent and well loved part of the series that is easy to neglect but would make a lot of sense to see implemented proper.
I personally think Octolings have much room to be Isabelle'd here, using weapons featured in 2 and 3 while keeping the Inkling as primarily 1-inspired. This may be an outsider perspective bleeding in again as well, since most of the time I see either the Sisters or Off the Hook, they aren't usually in combative roles story-wise, and while Deep Cut in 3 has actual fights, my understanding is that they are not as popular.
As I have alluded to before, I feel that, while not as dire as Ultimate, I feel the newcomer count for next game's base will be hampered a bit by the big amount of characters I expect to return initially, and to me, I imagine they will want to keep the newcomer list diverse series-wise. But I will concede that someone fresh (huehue) may be on the table if they go the lame route and make Octolings practically "Daisy & Richter in Ultimate" levels of clone.
My personal idea of a "meeting things partway" option could be having the Octoling explicitly be representing Agent 8 from Octo Expansion, they come with an Octo Expansion stage, and they would have a Smash Taunt that lets Marina and Pearl comment on one of the fighters like Palutena's Guidence and Codec Calls before them.
This is how I felt for a while, but I came around on it. I also think Mach Rider is insanely cool, and for a while (still, kinda) they were my most wanted retro choice. But Excitebiker speaks more to me lately in the context of Smash, creating a clear, streamlined premise around a simple Nintendo classic a la Duck Hunt or Ice Climbers. And Excitebike remains one of the most prominent pieces of early Nintendo arcade / Famicom branding, perhaps the most significant absent from the game right now. I still really like Mach Rider, but part of me feels like it's "too much" for Smash when the simple premise of a permanently mounted biker is already enough material to build off of. But I'd really like either of them.
To echo your words earlier, it's pretty much a "I'd have to see it to believe it" situation for me, to be honest. But like I said with the Zelda character, I won't lose sleep over being wrong about the "gag" character prediction...even though I think Diskun would be cool and also be a throwback to ROB's inclusion.
I'll say fair enough on Oatchi, I'm still not like 100% convinced and I also believe he'd make a fine Assist Trophy. But I also recognize the way Pikmin has become a central Nintendo brand, and I think it's ready to make the jump to a two character series. Oatchi has been a marketing machine, with plenty of merch to his name already, I'm seeing his face on juice pouches. I realize that this on its own doesn't warrant him to be playable, but I think it's worth considering just how much Pikmin's brand hinges on its creatures. Oatchi has kind of cemented this big new mascot that I think has a good deal of staying power. I'm not gonna die on this hill but I'll defend his placement.
Honestly...I want Pikmin to have a boss next time, if we're talking about the creatures (on top of putting in more enemies if we get Smash Run back). Again, this mainly is going off of me assuming newcomer spots are still going to be a bit of a tight squeeze here. I can see the character missing the boat in favor of more requested characters and other late-Switch headliners, this is far from the first time a series would weirdly miss out on a new character despite circumstances.
Tom Nook and Isaac are characters I'm very confident about. Nook for his level of mascot omnipresence for not just Animal Crossing but Nintendo as a whole, and Isaac for his presumably strong ballot showing. For what it's worth, Nintendo doesn't pump out a lot of big new IPs anymore so I think it's feasible that we are able to pull back toward an older one. Golden Sun got a surprisingly solid showing in Ultimate, so I really think he's one of those characters that would have made it had the crop of newcomers been "normal". And Animal Crossing really speaks for itself. We can split hairs on how much potential Nook has on his own (I've defended it frequently, for what it's worth) but I seriously think AC's series growth is too massive not to account for. And Nook kind of took a backseat in New Leaf, but Horizons re-established him as a major player equivalent to Isabelle again. So I think the timing is right and if Tom Nook is on the table I see virtually no first party out-prioritizing him. Want to suggest also that casual audiences adore Animal Crossing, so similarly to Waluigi this is a character with a lot of pull toward those less intimately familiar with Nintendo.
I have no brakes with Isaac, I actually somewhat considered putting him on my prediction outright, but I'm not fully confident enough to not envision him having to fight for the "last spot" on my base game prediction roster. And of course, Nook is one of his opponents. I will say Nook has a better shot in my eyes than Oatchi, but some of the other characters or series I have seen push for (Ayumi, Takamaru, a Rhythm Heaven fighter, obviously Isaac) could edge out in terms of a face-value moveset diversity standpoint, some more likely than others. I think my feelings are going to have to be a "wait and see" situation--going off of Swamp's survey, Tom may have been fifth overall, but it's a very close fifth--Ashley, Krystal and Isaac were all in arms' reach distance of outperforming him (all of them had a difference with him of just 10 or less votes). Even if Animal Crossing is undeniably strong, I still think Tom has pretty stiff competition from a "what the fans want" angle.
Noah, Bandana Dee, Officer Howard. I guess the most I can say about this is the reverse of what you said to me, that in competition for these base slots I'm inclined to advocate for at least Isaac and Nook first. BWD has a strong case given his popularity, and I'm not opposed. He could replace Oatchi if you want, although I'm perpetually skeptical about Kirby's character lineup. I do acknowledge BWD's demand and frankly how much he deserves it at this point - particularly after Star Allies and Forgotten Land. He just narrowly misses the boat for me.
I'm less convinced on Noah, although I couldn't fault anyone for it. I just think people overestimate the necessity to have a Xenoblade 3 character on the roster. Xenoblade is still a relatively small series, and I don't mean to be harsh but XB3 did not rock the world the way XB2 did. I'm not saying this means it absolutely won't get a character, but that Pyra and Mythra are still viable representatives for XB's growth on the Switch. Consider this a character that I wouldn't be surprised about, but I'm personally not hedging my bets toward. And the same goes for Astral Chain, a game that has seen fairly decent success but I'm not convinced this is batting any higher than "AT level" first parties from Brawl era like Golden Sun or Sin & Punishment. Kind of a gut feeling, but I did acknowledge the relative lack of new Nintendo IP. So if they wanna pull something, or Sakurai feels inspired, then it's a decent option but IMO inessential.
Truthfully, Waddle Dee on my prediction roster used to be a second Fan Pick placeholder, as he was the one character I intially could see things going either way, and it was him briefly topping Swamp's survey that was the push I needed to give him (or at least his species) a solid spot. In hindsight, it is easy to make excuses for him missing previous games--Smash 4 had its lineup decided before HAL became more committed to the character, and Ultimate had very little room for new first-parties, particularly ones coasting on demand. However, I feel the status quo has certainly been shaken up since then, particularly after Forgotten Land became the new #1 Kirby game in terms of sales, which heavily features Waddle Dees in general. Admittedly I was a bit cheeky and had the slot be a generic Waddle Dee slot--I don't realistically think Sakurai would be that cheeky/petty to focus on the generic Dee over the spear-chucker many of you love, but I don't know the man personally any more than any of you do. But the main point is that it's hard to deny at the very least how much Waddle Dees as a whole have been pushed by HAL, between their prominence in FL, having an April Fools' joke dedicated to them, having Mr. Bandanna himself being assigned to Player 2 in a good amount of recent games (including being the first Dream Friend you obtain in Star Allies IIRC). I think this is all going to hinge on the do-or-die moment of what Sakurai does with Kirby representation in general next game.
XB3 may not have reached the highs of 2, but being lesser than the previous game didn't stop us from getting Corrin, who I felt was less justifiable from a series growth standpoint when they got in. I know it is a low hanging fruit to point out, but the various flavors of RPGs seem to be the Smash devs' bread-and-butter with choosing characters to translate to Smash, and I doubt much will change here. I am not sure if the "viable representatives for growth on the Switch" comment means you'd sooner expect a character from a hypothetical Xenoblade 4 on the next system--but (correct me if I'm wrong) I believe I remember seeing something impying that Monolith was taking a break from the series after 3 to do something else. I don't think there is any harm in expanding the Xenoblade fighter lineup further currently. If 3 proves to remain unpopular even after future installments come out, I also think it wouldn't be too much of a loss to cycle out Noah and his cat-ears friend on a future roster with someone more notable. I know it may be unfair to lump Xenoblade in with Fire Emblem and Pokemon in terms of becoming a cyclical series, but other than the possible aforementioned thing of Monolith maybe taking a break, I don't see any justification for the series to end either like how Mother did. Regardless, I think Noah feels in line with a good amount of characters that have also been added in the last couple of Smash games. The devs love their humans with big swingy things.
As for Astral Chain, the main reason I cling onto it currently is simply because there isn't really much else in terms of brand new Switch IPs without characters, and any new IPs made for the next system will likely have to arrive late with DLC. I think it is unfair to compare it to Golden Sun and S&P's situations, since both series were skipped over during a time where there were a lot of potential options for fresh series to get in the game. If AC was still under Platinum's thumb, I would be singing a very different tune, but Nintendo's acquisition tells me that they see some value in the property. I think we'll have to wait and see if a follow-up comes quickly for the next system or not.
I'm sorry if they bore you, but I really don't see Zero being prioritized over Chun-Li. On his own I understand his value, and I get where you're coming from with his assets already being present in the game, but if we're expanding on mainstay third party series then Chun-Li is pretty much the absolute biggest no-brainer available. She's a character with strong crossover appeal, where being able to pit her against Peach or Samus feels like a selling point in its own right. She's one of the single most iconic video game characters absent from the game and pretty much justifies herself on her own star power, independent from being a second SF rep. Zero is great, but I personally think he gets eclipsed here and I don't see myself budging on that.
Genuinely, my only hold-up is that every third-party addition to Smash so far has had an obvious gameplan in terms of adding content, which is why my needle is towards Zero. When Ken was added to Ultimate, he brought practically the entire Hyper Street Fighter II OST, spirits for every SF2 fighter, a Guile Assist plus an arrangement of the family man's theme PLUS an extra arrangement of Claw's theme, and a dedicated World of Light section based off of SF2. Ken basically brought in all of the Street Fighter II-relevant content that was missing from Ryu's Smash 4 inclusion, and to me, that honestly leaves Chun-Li in a void of uncertainity. Yes, she could bring in content from later titles she appears in, but I doubt people want her because "oh yeah, she'd totally represent 3rd Strike/Street Fighter 6!" It honestly feels like Ken stole her thunder in that regard, and I wouldn't have had any qualms if both had gotten in at the same time in Ultimate. That is pretty much one of my sticking points towards favoring Zero, since the X side of Mega Man is still pretty bare and Zero would be an obvious patch for that hole.
Monster Hunter I can go either way on. They aren't a character that I personally feel all that strong about. But MH already has a showing in Smash, and has seen sufficient growth in the time between Ultimate's release and the present day. It's absolutely massive overseas, MH World became Capcom's best selling game, and MH Rise was a hot Switch exclusive. If this doesn't happen I won't be surprised, I'll be convinced there really is just some reservation internally about making a generic Hunter playable, but I'm willing to give them one more chance.
I actually think there is an easy solution to this problem in my eyes, and it's actually a solution that has been done before in the series; give the series everything a fighter-represented series would have, short of an actual fighter, just like with Animal Crossing in Brawl. While AC did get playable characters later on, its treatment in Brawl means that there is good precedent for a solution like this being done for another series that is less player-character focused in promotion, like...well, Monster Hunter.
I get that, this is one of those things where I can't fault someone for just abiding by the status quo. We don't really know what the deal with indie fighters in next Smash will be, but I think Undertale is like... just WAY bigger than Shovel Knight. Compared to Undertale's viral worldwide success, its remarkable popularity in Japan, Shovel Knight is absolutely trumped. I personally feel this is a different case, where Undertale is straight up maybe the most crowd pleasing western character that can be added from an overseas perspective. And I think it's fair game for base roster just because the negotiations for indie properties are probably much less difficult and Toby has already been a very willing participant. IMO this is a great bang for your buck pick.
As for Kris, I just don't really get this perspective. Undertale has had nearly 10 years to establish its legacy and popularity and Deltarune simply hasn't and likely won't surpass that. I'm absolutely loving everything about Deltraune so far, but if we got a character I'm certain it would just be from Undertale. At least for next game, maybe by Smash 7 Deltarune will have firmly planted its full release as Toby's magnum opus.
My primary hold-up with Undertale is that it feels borderline incongruent with the "protagonist-first" mentality Smash has used for nearly every other series, and has only slightly been bent for ARMS (and this likely wouldn't have happened if Ultimate came out later in the Switch's life than it did, tbh). The morality system with the Fallen Children feel like a headache to work with in a Smash context, on top of the children themselves not being the ones marketed in merchandise. Sans moving out and about and taking hits like other fighters feels OOC, and the other boss monsters outside of probably Papyrus all kind of share equal importance enough for me to have a hard time selecting one as a representative. It's not like something like Cave Story, Shovel Knight, Hades, Touhou where I could easily say "yes, the player character would fit Smash well enough from a character and gameplay standpoint".
My perspective for Kris was that, even though he is as much of a mute as Link or the DQ Heroes, he is much more easy in my mind to pin down fighting-style wise than Undertale's fallen children, since Deltarune has less emphasis on the "kill-or-spare" nature for its combat sequence. But I did say I only envisioned him as being a late, late DLC character for a reason, being that I can only see Toby wanting him as a fighter once he's got the remainder of Deltarune fleshed out and finalized. I guess as it stands, Undertale is indeed probably the Indie ever, but it's in the awkward position where both of its seemingly-obvious first-picks are very, very unclear in terms of how they could translate to Smash smoothly.
would still be easier than anyone from Five Nights at Freddy's, at least...