SE's talk of a 'new' type of content (for the game, not for an MMO) coming in 2.1 possibly indicates they'll be adding a traditional daily grind it seems to me.

They won't 'reset' the quests, it's not SE's philosophy, they' see doing that as making it too easy and profitable item/gil-wise.

In FFXI they allowed you to change nations and replay the main story missions for your new city, some were unique with some common to all, but in XI of course you never got XP for doing quests, given you do in XIV I think Hell would freeze over before SE give XP for repeating the post-15 main story stuff either.