I dunno. Sephiroth kind of killed the notion that Squeenix is unwillingly letting SORA use their content; really, the only thing holding back Geno is competition from other franchises like Chrono Trigger, TWEWY, and even Kingdom Hearts. At this point, not only have I given up believing in chances some characters have, but I’ve also abandoned the notion that characters never had a chance to begin with.
That's not that true, though. It's not Square characters holding Geno back. Square was always willing to at least lend their characters. Sephiroth doesn't pioneer anything new in that department.
It's that Geno is a supporting character owned by another company, from a single spin-off receding further and further into the distance as time passes. The relevant competition isn't "bigger Square characters" so much as it's just third-parties who aren't in that unenviable situation. Of which there are countless.
It's not a matter of them going "you know what, it's time to add another [INSERT COMPANY] character", because they don't do it that way. They just look for characters based on series, or character. They didn't add Joker because it was time to give Sega another character, they added him because he's Persona's most prolific option. So even if all the other plausible SE characters get in, Geno is still left being Geno, with all the shortcomings that entails. And therein, characters from other companies probably look like a better option from Nintendo's vantage.
I don't know. Crono kind of reminds me of Banjo in that he's an extremely popular character, despite being from a relatively small series. And also like Banjo, he's very synonymous with Nintendo given that his heyday was on the SNES. I know characters like Cloud and Joker make people believe that being on a Nintendo console isn't all that important anymore, but it's definitely still a factor. Even if Cloud and Joker aren't Nintendo characters, FF and SMT still got their start on the Famicom. Kingdom Hearts and Tomb Raider have pretty much always been Sony things.
Geno's situation is so unique that I don't even know where to begin with his chances. Chrono Trigger and Super Mario RPG were on the same console and both did very well. Crono was the main character in his game though and had his name thrown around with the likes of Link and Cloud. Geno's popular, but he's never reached the level of popularity that Crono had in the late '90s-early 2000s. Also we have good reason to believe that Square isn't interested in seeing Geno in Smash. I think I'll leave it at that.
I think all of these characters have merit. Crono just seems more like a character Square and Nintendo would want.
Crono is sort of like Banjo in that they have a legacy of affinity and are well-regarded, well-liked characters people would be happy to see, and wouldn't strongly protest the presence of. But they're unalike in that Crono isn't extremely popular in the way Banjo was, which is within the fanbase. Things are going to have to shift drastically in his favour to end up in the position Banjo was in. Otherwise he's just going to remain a darling within certain circles but a character not really at the forefront of anything anymore.
And to be fair, Banjo would've been included a long time ago had Rare and Nintendo not parted ways. What really drove Banjo's popularity is the history he had with Nintendo, and as one of their characters. Crono has a history with Nintendo, but a much more standard one for a third-party.
To that end, I do question whether Nintendo history is really a pertinent factor. Think about it. Nintendo history can inform demand, and demand affects inclusion. So it
indirectly can matter. But look at the inclusions with the very strong Nintendo history. Mega Man, Simon, Banjo... these are the characters explicitly included due to the demand. I guess you could make an argument for Bayo, but until Nintendo adopts Crono, it's not really applicable.
And just having some key titles on a Nintendo system at some point is a pretty weak litmus test for history, considering most if not all of those examples, like FF, SF, DQ, etc. can also apply to Sony.