I feel like it's going to pull a Rebuild of Evangelion. It will try to follow the original plot but will eventually go off rails and turn into something new. If the dev team was smart though... they would set up future installments to give the player the option of following the original plot or give them the option to make choices in-game to go in radically different directions. There is a part of me that feels it would be interesting if you could thwart Aerith's death, but now it means Tifa dies instead. Things like that would be neat.