I suppose it really depends how they do it. Cameos are fine in special content and whatnot for events and stuff but i don't see a need to cross over anything from previous games. The fun of Final Fantasy is supposed to be about many different worlds and stories with just a few common themes wrapping them together. When you start bringing in characters from other games it just makes giant confusing plot holes of doom.
If they want to promote a new game with some sort of special event sure that could be fun but making them part of the game would just be weird.
If they want to promote a new game with some sort of special event sure that could be fun but making them part of the game would just be weird.
