Island Sanctuaries - End Game Only

[Rowde]

The location would be the biggest reason it's tied to the end of 6.0. It seems to be somewhere in the area of Thavnair, which we've only just discovered.

What sense would it make to be going through the story, just barely getting into Grand Companies and then "oh hey, here's a tropical island for you"?

is it though?
nothing about the exposed sediments or fauna scream thavnair to me

I think it looks way more reminiscent of La Noscea and Hullbreaker Isle