Yeah but at that point, the planning could also happen around the time where they're already doing the final touches on the base game, like what happened with Fighters Pass 1.
At that point where Smash 6 and Gen X are actually coming out, yeah. But that's not when they'd first discuss the matter. If in their initial talks, at the beginning of development, they realize their then-current gen would no longer be current, they may look forward, if promotion remains a priority to them.
This would not be a decision Sakurai would take on Day 1. It would be handled very late in development alongside all the DLC.
I know Pokémon has a reputation for being the only series in all of gaming with early bird privileges when Sakurai makes a roster but to assume Sakurai would spend entire years doing **** all about a planned Pokémon just to time it with a Gen release as DLC is a complete opposite of his work ethic of not touching DLC until the work on the game is done. (Not that I said the game being done, not the game being released, these are two different things)
You're basically going off on an assumption that Sakurai is outright lying to everyone about how he develops Smash to build this theory.
Sakurai's work ethic would remain as it is, this whole decision would be at the behest of what TPC wants. They clearly have tight control over the Pokemon newcomers. They would be the ones who would want the character to coincide with the gen at hand, and if base didn't mesh but DLC did, their requests very well may reflect that.
Sakurai isn't the one deciding to leave placeholders for a year until he can get a hold of next gen designs. Sakurai isn't the one who decided among all Pokemon it was either going to be Incineroar or Decidueye. The entire catalyst of Pokemon's promotional representation comes from TPC/GF, and Sakurai goes along with it.
Do you think in his crossover of big names in gaming, with all the famous Pokemon out there, Sakurai is the one who would choose a character who doesn't currently exist as more than a drawing? Every time Sakurai has seemingly been allowed to decide a Pokemon, he chooses a notable Gen 1 (or Pichu). The entire decision-making process for the series in the last few Smash games is antithetical to Sakurai's MO; it's TPC's MO.
And this is absolutely how TPC operates in Smash. From the perspective of promotion, their newest gen will be the priority. In theory Sakurai could challenge them wanting a DLC character as opposed to base and fight them on the issue, but... to what end?
To what end is TPC's position unreasonable? They're not asking Sakurai to do more work than normal. They're not asking Sakurai to add DLC to a game that doesn't have DLC. There's no reason to believe they'd ask Sakurai to actually work on the character until work began on the DLC fighters. And all the producers and those who would sign off on Sakurai's project plan are obviously aware Sakurai defers to TPC on these sorts of things; it wouldn't reflect adversely on him to capitulate. It would be the status quo. Smash's development is not a testament solely of what Sakurai wants.
I'm sure Sakurai would rather choose the Pokemon character right from the jump. I'm sure he would've liked to do that the previous two times as well. I'm sure were it up to him, he'd choose Pokemon that are actually proven and established. But I also think Sakurai isn't going to stand opposed to TPC unless he has very very good reason to. And allocating a future DLC spot so they can capitalize off promotion doesn't seem like sufficient cause to me.
You're basically going off on an assumption that Sakurai is outright lying to everyone about how he develops Smash to build this theory.
- Sakurai said there weren't any plans for paid Smash 4 DLC after Mewtwo's reveal when they were almost certainly working on at least Lucas, if not actively reaching out to like Capcom and Square.
- Sakurai said Smash has never been turned down but also said they weren't able to land Snake for 4. I also believe they did try for Sora unsuccessfully for Smash 4 before eventually getting him, but obv that is unsubstantiated.
- Sakurai said Nintendo chose the Ultimate DLC and everyone just assumes he's lying and is still like "Sakurai chose Terry because he likes FF/KoF". Personally I think he probably did have some role in some of Ultimate's DLC selection.
- Sakurai has said characters have to carry game history with them, but when it's at the behest of another party, we also get characters whose games aren't even out when they were selected
- Also the whole ballot, from Bayo's selection to poising it as for 4 was pretty dishonest.
Sakurai has been less than upfront about development before. In broad strokes I believe he is telling the truth, but I also believe there are exceptions, especially when he is deferring to another entity who does things differently.