I still think we have a big surprise waiting for us in the bridge between 2.0 and 3.0
I'm still convinced Alexander is involved due to the designs on the throne in Ishgard cutscene, and on the walls.
They said their would be a big event going into 3.0 and I'm convinced that the Ascians will get Ishgard to summon alex to take out bahamut once and for all (since in the past they have gone up against each other)
And then expansion will deal with its fall out, sky zone could be shattered lands from the fall out