Noctis should make an appearence in the game eventually. But Sora won't be in it since the is a FF-only fighting game. Plus the fact that Disney owns the characters in KH and don't want KH characters in a fighting game like Dissidia.
I can't stress enough how much that pisses me off. Like what logic is there in that? Your characters are already fighting other Final Fantasy characters in your own games, what makes the prospect of having just one or two of them in a FF fighting game unappealing to you!? It's not like you're throwing Donald and Goofy into a pit with Sephiroth to die or anything, you'd be using Sora, the character that was designed to fight off FF and Disney characters alike! The hypocrisy just baffles me!!
Still, there may be a light at the end of this tunnel, with KH3 on the horizon, maybe Disney will be a little more keen to take whatever chances they can to promote KH in some small ways. I mean they featured Sora as a summonable champion in World of Final Fantasy, it's not too different from what you would do here. I mean, yeah I understand there's a fundamental difference in genre here, tactical rpg vs rpg-styled fighting game, but it's still the same in spirit, it's Sora being thrown into a crossover FF game, it shows that they are capable of letting go of the idea that they need to keep Sora away from anything that is not strictly Kingdom Hearts. It doesn't necessarily guarantee that Sora would be featured in Dissidia NT (if anything they could still be dicks and keep him out of it, making the double-standard even more frustrating), but it at least shows that there's slightly more hope of it being a possibility than before. Or at least, as much hope as there was for Sora potentially being in Smash 4 with the fan-voting, and even then that didn't turn out that way. I'm just saying it feels less like a "99% NO" now and more like a "75-80% No".
But Sora not being in this is one thing, I can understand and live with that (begrudgingly), but if they don't add Noctis into this at any time, I'm going to be convinced that both Disney AND Square have lost their marbles, may as well not have Link in Super Smash Bros 5 while you're at it.