In my opinion instead of a free transfer, just do a server merger. Merge ALL the low and medium population PVP servers together. Figure out how to manage Firstname/Lastname (Character name / Server name) and lump them all together on a server. Then reclaim all the unused server capacity to save money or rebalance elsewhere. Set it up for scalability during content patches. Make sure nobody waits in a long login queue. This is what everyone wants anyway. Nobody wants to grind 10k gold for guild bank slots on a new server and use some weird variant of their old server name because their name is already taken on the new server. If you want to include Normal and PVP in the merger, just use the pvp flag to manage. If not, merge the normal servers together to give them their own experience.
They want to see bodies in the cities. They want to see people in chat. They want to pug spots in groups. They want an active auction house. They want their character name.
They donāt care what the server is.
Layering algorithms will need more attention to make zones feel less crowded. Login priority may be a thing too. If someone has been logging in consistently and 2,000 offline players log in for the next phase, give the dedicated player priority. ā/played 30dā could be a metric. Better yet, just scale the server up during the start of a new phase and scale back as people log off.
In the world of virtualization, it seems like server capacity limits shouldnāt be a thing.