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.

IMO, there are ways of implementing turn-based and modernizing it.

XII had free-roam, but still kept a mostly traditional ATB system (cool downs and cast times being the non-traditional aspects).

XIII just stacked the ATBs and let you perform a series of attacks at once.

XVI used ability cool-down as a stand-in for ATB.

XV is the only one that has really dropped the ball, imo.