So, we will explore The First in 5.0. Though we are going to visit what we could say "a parallel Eorzea", it's not Eorzea. So 5.0 may be the first expansion in which we won't see anything new of our realm.
So I ask... Are there any chances to visit more new zones of Eorzea in any future? Maybe even new zones available for 2.0 players so they can use flying mounts. For example, some of 1.0's reworked: the southern part of Mor Dhona, the West Shroud, the Coerthas Eastern Highlands (with Rivenroad's ruins :3). An openworldly zone of Carteneau...
I see there's another unvisited region: Paglth'an (though I imagine this similar to the Peaks).