The issue of a big population, which was highlighted by Alexensual in https://www.youtube.com/watch?v=I3LM_uImxhM, is lags and queues on login.
He thinks of oppenning all 3 servers at the same time. It allows to distribute population on 3 servers.
So, as my suggestion, open not 1 fresh PVP server, but open 2 fresh PVP servers instead. It will help with population distribution. After some time, when players will be on different zones of world and server loading will be lower, these 2 pvp servers can be merged to one server.
It's just my thoughts, I don't know tech-details...
