Server transfer is always an uncertain affair from FryeJacob's blog

You would also have to limit the creation of WOW Classic TBC Gold Horde-related characters on all servers within the bgpool. It's not really feasible, or is it?

And people had the chance to exchange short queue times for quite a time. However, they did not. Because they didn't use the free transfer of servers. This isn't really unusual for me, considering that most people play their favorite team or are where their friends play. It's hard to change this.

It's not a great argument to have balanced servers or a Bg pool. Additionally the possibility of changing factions will mean that they can now play with their friends as alliance, instead of the horde.

Server transfer is always an uncertain affair. It's impossible to tell the quality of your new server better or worse than your own. Vanilla was my first experience of seeing this happen. My guild moved to cheap WOW TBC Classic Gold a new server, and the number of players dropped to a few hundred during peak hours.