The gameplay was changed, but it was changed way back in E3 2013. The game in its current state will still play like E3 2013 when Nomura was at the helm.
It's becoming clearer and clearer that a lot of stuff from E3 2013 has been dropped. That's the most frustrating part for me. Removing weapon switching did not bother me that much. Changes in the battle system didn't bother me that much. Even Stella's removal doesn't really do much for me... but:
-Dropping multiple playable characters
-All the beginning section cut
-Possibly no more Leviathan sequence while swimming (it was arguably the E3 2013 trailer's "wow" moment)
-No more warp outside of battles, most likely removing verticality in exploration
-Part of Nomura's feel/"esthetic" gone along with him.
Those changes are making me more and more nervous.
Fans have waited from 2006 to 2013. We were told the game had been rebooted, fine. That news came with a whole new set of promises, and a lot of them have already been broken. Can't blame people for being disappointed.