Iris and Cilan will still be there. Mostly Unovan Pokemon will be in it. It's set in Unova.
Even though it has one Pokemon from the next generation, it's not a Generation 6 movie. When the new anime for Pokemon X and Y come out, and a movie is made with the new characters and set in the new region with mostly Gen 6 Pokemon, it'll be a Gen 6 movie.
I'm not hoping for much from CoroCoro. I think it's because of Pokemon Smash. I have a small hope that they're just making us not expecting much and then giving something good, like the region, but not much faith is left in me.
But that's exactly what they want me to think. Maybe.