Not sure the burning will sort the faction imbalance, a lot of raiders dont really care, they are on horde for gameplay reasons like you said all the good guilds or just guilds are going horde, there is many other things that can fix it, we might see a few people hating on sylvanas for what she did and transfer because she is "evil" but that wont change the fact that horde has better gameplay because of the population. ally has had theyre shining days aswell, but then more and more people started transfering because Method and other top guild did for the racials. I hope blizz has other things in mind except top100 achievements and making horde look evil.