Based on the information provided by the official FFXIV website, we now have dates when we can expect the data center expansion to happen.
Europe will get a new Data Center, Light, on Tuesday, 2 April, 2019.
NA will get a new Data Center, Crystal, on Tuesday, 23 April, 2019.
Servers from existing Data Centers will be broken out and moved on to the new Data Center like this:
Because this may separate friends who have made connections across Data Centers, it’s been confirmed that ALL characters on ALL servers will get free transfers for a period of time.