I am not sure about exact implementation of this, that would be least harmful, but it seems that long term benefits of having location (time-zone) based servers would resolve a lot of issues.
Pros?
- More balanced population at given times (one time zone)
- Less requirements for language specific personnel (i.e GM etc...)
- Better ping, spells that cast 0.5s go to 0.7s with 200ms ping. Closer servers can contribute as little as 0.02s to cast time.
- Possibly good long term effect ?
Cons?
- Short term bad effect on current populations
I think it would be safe to assume that
- Players would have a choice where they want to migrate
- Most players speak English nowadays, except for some dinosaurs, it's basically a requirement for many jobs.