Seeing how I’ve seen a lot of arguements with DLC, I’ll sprinkle in some of my thoughts.
I think both Sora and Geno can get in.
With Sakurai mentioning Geno being popular, I think that already sets in stone that Geno will still sell well at least. Geno isn’t that undershowed as people are making him out to be all of a sudden. Yeah, I guess SE can be a bit a bit of a pain to work with, but I think with DLC, negotiations are a lot easier to make. And by having Sora along too separately, it may be a deal SE would at least be content with.
A Gen 8 Pokémon and FE: Three Houses have zero chances of getting in the first season.
If Sakurai couldn’t get Rex and Pyra on time, he sure as hell wouldn’t get characters whose game would only be in deep development at the time and come out around 1.5-2 years later. I don’t think either are in in the meantime. (Plus we don’t know if the 2019 game is Gen 8 to begin with).
Some of the DLC characters are those Sakurai wasn’t able to get in the base game.
Hence, why I think Sakurai said he started planning who would get in around 2016-2017. He realized that with the current scope of the game, some characters had to be prioritized over others. It’s why I think Elma is likely all of a sudden since there isn’t any X content and Monolith Soft went the extra mile with Elma with the amount of interactions she had with the other characters. Same could be said to Geno and maybe with Sora since getting rights for them and the other third parties could’ve been a bit too much.
However, I don’t think all of the DLC characters were decided along with the base roster. Sakurai was pretty clear that he doesn’t think of all the DLC at the very beginning, so some of them were decided later on.
Some ATs, Spring Man, and Rex’s costume are all meant to be consolation prizes.
Seeing how Rex and Spring Man were popular characters, I think them having references is all Sakurai was able to do in the time to at least give those fans something. Heck Sakurai was pretty clear with Rex on that one. The same can be said for Isaac. Isaac was an extremely popular character with a lot of support, and seeing how he was updated, I think it was something the team was able to at least manage to get in for GS fans. Isaac is another character I think was meant to get in as playable but couldn’t due to time contraints and the game’s scope.
However, I think they have a chance for at least a Season 2. Seeing how they are all popular, and how King K. Rool’s costume was also meant to be a consolation prize only for him to be a fighter, and the fact that since the Switch is more successful, we can potentially get more DLC past the first 5. I think Sakurai is at least considering them for a potential second season of Smash DLC.