Spirits are not fun. WOW is designed is to be with friends to play together!
Blizzard whole role in the research for players to move to the new server convenient point method.
Spirits problem is not simple solution, especially this kind of situation: the players hear mar ganis the PvE server atmosphere is good, or the Kang Derui server PvP atmosphere is good. In this way, players will be transferred to the large population of server, or in the server to the new number, so popular server is more and more crowded, spirits and die faster.
Close or close under is unlikely, because a lot of players on their own servers are have feelings, still have players like their role name, they don’t want to forced emigration, or forced to change name. (this is for European and American clothing)