I have one thing to say.....

Eulmore clearly isn't just 'built on the remains of Limsa Lominsa', it literally is Limsa, or rather, the First's version of it (remember, this is an parallel world, things on Hydaelyn's Shards didn't turn out the same there as they did on 'our' Hydaelyn, like the First's version of the Crystal Tower being intact and having a city built around it.). It doesn't even look like it's surrounded by ocean but land that sprawling slums have been built on (and the foundations of which are presumedly where Thancred and Reborn!Minfilia are running through.

We'll find out in a few months either way.