To answer simply based on the impression on the dev team. They still have more stories they want to tell with the FFXIV world.

There is still a lot of mysteries and unexplored threads regarding the world such as Meracydia, Ilsabard mainland, Aerslaent, and the New World (especially that since thats actually the biggest continent in the world I think)

We also still dont know the ultimate fate of the 13 shards of Etheirys.

So yeah I feel theres still more room to explore with FFXIV.