Also alongside all the stuff I saw a couple pages back about it being "too early for Smash", I personally just don't think the 2021 project being Smash makes any sense at all.
Every Smash game since Melee has started development a year before their console comes out, which would point to last year, not 2021/2022.
Sakurai said his project plan was drafted "lightning-quick" but with he himself saying Everyone Is Here is unlikely to happen again, I will continue to doubt that the next Smash would be an easy, fast project plan to make considering things like hard decisions on possible cuts, because making a port would be stupid when the Switch 2 is already confirmed to be backwards compatible and can just play Ultimate anyway, plus Smash never does ports.
Bandai Namco, who has worked on the last two games and I see no reason why they would be left out, announced their Nintendo studios in 2023 and then began a big hiring wave until some time last year while ALSO making new Spirit Events for Ultimate, including events for first party characters, both of which make NO SENSE in my opinion to do when you're already two years deep into development of the NEXT Smash and instead make more sense to be stuff you do between projects, so to me it feels like I'm being told "Namco isn't involved even though they literally made Nintendo support studios" or "Namco is involved but they kept their support studio hidden and had MASSIVE turnover rates for some reason".
In my mind it makes a ton more sense for Sakurai's "lightning-fast" project to be a smaller side project, possibly as a launch title for the Switch 2 like Kid Icarus Uprising was supposed to be for the 3DS, and then nearly two years into its development, Sakurai drafted a project plan for Smash on Switch 2, Namco started hiring to put the team together, and it began development when the Spirit Events ended and the hiring was finished, tying into Sakurai's statement of typically going from project to project seamlessly while also making it last year, which would likely place the next Smash somewhere in 2026/2027 range for release.
I'm not gonna argue about it with anyone specifically because at this point it's opinion vs opinion, but that's just my thoughts on the matter.