It sounds like Final Fantasy XV might see sequels in the future, similar to Final Fantasy XIII.
When asked about potential sequels at their presentation in Los Angeles this morning, Square Enix stated that Final Fantasy XV is such a large-scale game that many stories may come at a later time.
Square Enix’s Final Fantasy brand director Shinji Hashimoto wouldn’t comment on how close to completion Final Fantasy XV is. The game is still being worked on by the same staff that were developing the game when it was titled Final Fantasy Versus XIII, although Hashimoto stated that Square added staff to the development.
Hashimoto also stated that, having played Final Fantasy Versus XIII on PlayStation 3 and Final Fantasy XV on PlayStation 4, he can see the difference between them.
When asked if the more action-oriented nature of the game meant that Final Fantasy was going to be become that way in the future, Hashimoto stated that the Final Fantasy series has different systems, but that Square are not at the stage where they can comment on the future beyond Final Fantasy XV.
When asked if it was difficult to do turn-based combat in a game that has the production values of Final Fantasy XV, Hashimoto stated that he feels there is a future for both action-based RPGs as well as command-based ones. Square feel that the action-based combat fits Final Fantasy XV.