Interesting but ultimately non-answer about turn based combat returning to Final Fantasy.
With this question of turn-based versus action, it tends to isolate the gameplay to just the battle system. That doesn't take into account what kind of game the creators want to deliver to players. For example, based on a certain graphical quality we want to present to our players, or the narrative we want to deliver to our players, it relates to how we set up the game's systems around it. This includes the battle system, game design, and gameplay feel. It's not a clear-cut answer, whether it will become all turn-based, or if it's going to become more action-based.