I think too way too many people are on the hype train for Sora. No leak has been credible since Terry. I'd bet however than Sora is going to be added as a Mii Costume at this point
It happens every time a reveal is on the horizon. Sora is one of the main potential fighters that gets a enormous amount of hype behind him. The supposed leak only added fuel to the fire.
Sora is my most wanted character, and Tuesday is all or nothing for him making it into Ultimate. Do I believe the leaks? Absolutely not, but I am hopeful yet cautious going into the reveal. It’s most likely going to be a Pokémon, or someone out of left field that no one saw coming.
Either way. People are going to be disappointed.
Just a few things to point out, Disney is all about the spotlight and making coin, if Sora isn’t the star of the presentation, they wouldn’t bother, nor do I think Nintendo would go through the hassle of making him just a Mii Costume. Also, if Sora was always planned to be a Mii Costume, he most likely would’ve been revealed as such within the Sephiroth’s reveal.
I want Sora. I don’t think we’ll get Sora. I hope I’m wrong, but we will all know soon enough.
Edit: Not saying it’s impossible for him to be a Mii Costume, but a very slim chance. I believe either Sora is FP11 or he isn’t in at all, in any context. And honestly, I would rather not have him at all, rather than a Mii Costume.