The are no first party big names left to add. It's been B tier since Brawl.
Someone already said Toad, but there's also Dixie. Plus majority of Melee's additions aren't exactly what you call Alisters.
This right here is where we disconnect. You seem to think Smash Bros, as a series, has a definition written in stone. This is not the case. You can avoid mentioning Goku with all of those other names, but the principle stays the same, they all challenged what Smash was thought to be at the time and forced people to change their definition, as Sakurai often does.
Before Brawl came out, Smash was a Nintendo all-star game, and now it's a celebration of videogame history. Not that Goku and other 4th party characters haven't been part of videogame history, but my point stands. The next Smash could be (if Sakurai wanted it to be, and all the legalese is sorted out) a celebration of pop culture, forcing everyone to change their perspective on what Smash is to them yet again.
Would you sit here and be salty, not accepting the new route Smash Bros chose to go this time around, or would you be mad for like, a week, and then open your mind to the new possibilities? Maybe you're right, maybe adding 4th parties would be the straw that broke the camel's back, but it's still my belief that once the character is revealed, and Sakurai does the rounds explaining his new philosophy (which seriously guys, he changes his opinion all the time, y'all need to stop bringing up old stuff), that everyone would settle down and learn to love it. Maybe I'm wrong, but I don't think so, I've been around this scene for too long.
Here's the thing, all the 3rd party characters still have a clear connection to Nintedo history, Snake had a game published by Nintendo, and even Cloud's series has had games published by Nuntendo, outside of Japan
And also her's the thing, Smash prodamintly loyal fans are Nintendo fans, meaning the ones who show up, and who they make money of off. Plus turning Smash into a full on video-game character, let alone a everyone goes fighting game, means a licensing nightmare, and a gareenteed no profit made, by anyone evloved, because every character not owned by Nintendo, would constantly be handing them notes, and telling them what they can and can't do.
Which means the game would never be released, cause you'd have to palcate every rights holder involved.
Honestly? 4th Party doesn't exist. It's just a silly term made up for 3rd Parties because they didn't come from a video game first.
Anyway, I wouldn't be all that bothered by Goku, but he's just another neat 3rd party.
Also, Smash stepped away from "Nintendo All-Stars" quite a long time ago. Sonic was indeed attempted to get into Melee, but there wasn't enough time, and I think Kojima asked about Snake as well before Melee released. The only reason was again, not enough time. Basically, the whole "All-Star" thing is at best only really for Smash 64. It wasn't important since then and the premise of the series does not indicate nor force the series to adhere to the old design. It evolved outright to include more stuff. And there's nothing wrong with that.
Eh, not really, Smash is still prodaintly a Nintendo fightet since the 3rd party characters are still listed as guests. Plus, as I said they all still have some significance to Nintendo.
Also for those of you who Goku is the only character left who can bring the hype level, that Cloud brought, as well as destorying some rules the fans have, as people here have said, we still have ones like Master Cheif, who would bring in Cloud level hype.
Though I question if Master Chief would bring in many new people to Smash, since well, most Xbox fans are mostly FPS fans, and I'm not sure they'd want to spend the cash for Smash and a new console.
Anyhow getting to what I actually wanted to post.
Here's what I think are the most likely newcomers to happen, from series not with playable characters in Smash.
First, what I believe is currently the last missing longest running Nintendo series, the Nintendo Wars series. Basically I see them potentially getting a rep this time, most likely Andy, since he seemef to be the main character of 3 of the games. Basically I see them adding a character from here if they want the currently last series that originated from the Famicom, to be added.
Now onto the modern series. I see Dillion and Mallo to most likely to get the jump to playable, since now that they have multiple games, they've proven they've got staying power and a fanbase that will show up for their games.
Now the 100% lock to me, if the Smash team can get the characters mechanics to work, and that's obviously a Rythm Heaven rep.
Basically my thinking is, if they can properly get the rythm idea down for them, it'll happen. But I'm not how they could do a rythm based moveset, when they potentially may have to take stage songs into account, to do the rythm idea, but maybe not, after all DK's final smash is rythm based and all that needed was a visual cue for the timing, so they'll probably do the same for a Rythm Heaven rep.
Also I'm not on an ARMS rep, since even though it sold well, Sakurai and co. could still sit on a ARMS rep, since they may not be sure ARMS has staying powet, after all Sakurai has sat on new IPs before, and wsited for the next Smash, as a way to see if the IP has staying power.
And finally, this is something I only see happening if fan demand was met outside of smashboards, and that's Isac getting the nod.
As for retro and series with characters in Smash already, I'll talk about that later.
But I have an interesying question for you, we all know about retro reps and how Pac-man takes from Namco arcade games. Have any of you thought of a character who would represent Nintendo era arcade games?
Ones that aren't Donkey Kong obviously.