>>40982817Most gens have a regional dex, and probably a few mons you can get outside of that, but you are not able to catch them all right out the bat, at least not in the first games of that gen, so that would not be anything new. We used to be able to transfer from bank or previous gens, after a certain point, so you could get a "complete" dex that way.
The idea now is that you can only use whats in the dex. That means no transferring Pokemon from previous gens, unless they're included in the "regional" dex.