FFXIV patch 6.18 will bring with it the Japanese data center expansion with Meteor as a logical data center and European data center expansion with Alpha and Raiden on Light and Phantom and Sagittarius on Chaos.
First, there will be the typical two-week grace period for FFXIV Home World Transfers following the Japanese data center expansion and European data center expansion.
The FFXIV Japanese and European data center expansion details are here.
There are also some new world bonuses connected to the FFXIV European data center expansion.