So, I was having some conversations with some friends who aren't super into Smash speculation like I am, and I noticed something really interesting come up when I asked them who they'd want to see.
Consistently, Sora from Kingdom Hearts came up. Like, more than any other character by far.
Here, we have a tendency to dismiss Sora due to his rights being owned by Disney and not Square Enix, but I'm beginning to think we've seriously underestimated how heavily requested a character he is. He's one of the few characters I can think of that would create a level of hype that rivals Cloud's reveal.
I've been trying to find any evidence I can of Disney and Nintendo working together, and there are examples, though sparce ones. Nintendo published
Disney Art Academy for the 3DS, a game which is filled to the brim with Disney IPs.
Less recently, Nintendo created several products featuring Disney characters (most notably Mickey Mouse) in the 1960s and 1970s including three
Game and Watch games, several
playing card decks,
board games, and
alarm clocks.
Disney-centered games have also consistently appeared on Nintendo platforms, including games from Disney Interactive Studios and the Disney Infinity series. If you want to branch out, Disney also regularly licenses its characters to other companies to have them develop games, including Square Enix and Capcom.
With this much being said, it wouldn't surprise me terribly to see Nintendo approach Disney, whether through Square Enix's contacts or on their own. Disney and Nintendo have had a good working relationship for some time now, and Sora's demand (potentially from the ballot) could easily be what makes Nintendo take the plunge to negotiate with them. Heck, I could even reasonably see Kingdom Hearts Mickey, Donald, and Goofy appear as part of Sora's final smash or in trophies if including Disney's mascot is part of the agreement.