Apologies for the round about way of uploading this for you to view, however remember back in the summer event, the background they had for the posing by the beach? The one Naoki Yoshida had as a background as well, it looks a bit more like the tropical beach idea you have - it has palm trees and such...though the area may exist in the game at the moment and I've just not seen it.

As a side note, if you check the 2.0 PDFs, the XIV symbol in the bottom right hand corner of the UI mockup is the same XIV symbol they are using for the Legacy campaign as well...it just makes me think what I say may be plausible hehe