I don't know about that. I'm willing to bet they're someone no one's gonna see coming. In terms of Sora, too, I feel his chances are just as shot as the other 'disconfirmed' characters for FP5 (Doom Marine, Geno, Lloyd, Crash, etc). If insider word on disconfirmation for the Fighter's Pass means something, then this still applies to Sora, as he was blatantly disconfirmed via the Square Seven list (the only character apart from Geno who was said to 'definitely not be in' the Fighter's Pass). That means either disconfirmed characters by insiders actually still have a shot, or none of them do, which would include Sora. I'm more leaning towards the former, not because I expect them, but just because of healthy skepticism doses. I don't like taking insider word as gospel, but as something of note to consider.
It's kinda funny that people are so quick to be like, "HAHA (X) BTFO," for FP5, yet Sora's insider 'disconfirmation' seems to have been conveniently left out. It applies to all of them, which includes Sora, as well as our star boy.
Post-pass, though, I'd be surprised if we DIDN'T get Sora.