Aussie Server

[Seraphor]

I really doubt they'll move any servers. That wouldn't be very good for non-Oceanic players on those servers, especially those with free companies or houses. It's more likely they'll offer free transfers to new servers.

There was a time when EU didn't have any servers, and the ones they moved to the EU were formerly NA servers.

Ultimately it depends on how many Oceanic players are on those servers, and how many will be moving.
If it's 50%, they could go either way.
Tonberry is by far the largest server in JP, with 77k (12k active) characters, with the next largest having just 50k (9k). It would not surprise me at all if it has a majority of Oceanic players.