Pardon me if it seems I'm over dramatizing this, but It feel like they're committing the same sins that ruined XIV in the first place. Trying to innovate and change things simply for the sake of changing them. Over analyzing some aspects while completely ignoring others when designing a system.

Now, from what I can pick apart from google translate, the simple horrible server structure doesn't allow for regular mergers. However, that shouldn't stop them from simply recommending certain old servers to new. Like say Lindblum and Istory recommended to 5 or something.
Something simple like that would greatly relieve the confusion.
If your friends are scattered through linkshells and doesn't choose the same new world..hey that just happens.
It really shouldn't have to.