Geno, and for that matter any other Square Enix Character's chances (that aren't from Final Fantasy), all hinge on the 17th.
Geno and Mallow being Mii'd in the same costume wave, let alone one focused primarily on Final Fantasy 7, bucks precedence seen with Hero's Mii Costume Wave.
Sora has an even tougher road ahead of him if he wants to get the fabled envelope. You have to have the green to convince Disney that Sora in Smash is a good idea, and also get rights to "certain cameos" in Sora's moveset if that's in the cards.
Crono has more issues in regards to the particular likeness that Sakurai would aim for. This goes back to a period of time where Akira Toriyama was legally represented by certain companies that would own his characters. You'd have to work out the rights to use Toriyama's depictions of the Crono Trigger cast for Spirits alongside the character himself.
Sorry, but I have to respectfully disagree. I think people keep making Disney out to be this giant boogeyman that refuses to budge, in reality Square is a tougher company to negotiate with (in terms of videogames). If you want proof Disney can be reasoned with look at all the content and characters they have given Fortnite. They allowed a Black Panther costume for Armor King in Tekken 7. And they allowed Nintendo to have exclusivity to Marvel Ultimate Alliance 3 and allowed Wreck It Ralph to be in the Sega All Stars racing game.
All of these properties are much more valuable to Disney than Sora is, who barely has any merchandise in Disney Parks. It would not be that difficult to convince them as for all the examples I just mentioned.
Now you have the roadblock that is Square Enix, iv said it many times in this thread. Square like cross promotion, they do not like putting guest characters that do nothing for them. Cloud, Hero, Sephiroth are all cross promotional picks. Even guest characters in other games are cross promotion picks like Noctis and 2B. Sora fits this crosspromoting agenda. If Sora does not happen, it is because Nintendo did not want to have a non gaming company in the credits, and have non gaming elements in Smash.
I saw that you said Geno has the highest chance for the next Square pick over in the Geno thread, again I have to respectfully disagree. This goes back to Geno's biggest obstacle is not Sakurai or Nintendo. Its Square Enix, they love cross promotion, Geno does not fit that. If Square allows Geno to happen its because they wanted to please fans, which is very out of character for them. Im not saying its impossible, but he has a 50% chance of happening. It would really have to be Nintendo and Sakurai who would have to convince Square Enix to allow Geno to be a playable character.
Again I want to stress Geno has a shot, but he is definitely not guaranteed to be Square Enix's next rep.