Single players games tend to have a story 'arc,' that begins, ends, and doesn't leave a lot of loose ends.

FFXIV's lore is gargantuan in size (seriously.) and we've only seen the tip of the iceberg. Frankly, I think it's going to take the entire life of this game to get all of the "Once upon a times" they've given us to their respective "the ends."

Though... I wouldn't mind... if they started working on a separate, isolated storyline that revisits the land of Vana'diel and gives us a replay-able, revisit-able adventure to give the Children of Altana a proper send-off....