They said they would base it on 1.12 yet they implement the old mount system.
Batching does not work properly: Classic WoW Batching twice as slow as 2006
We did not call for no changes, a small vocal minority did, the people that played private servers were all accustomed to changes, as it is very needed for this outdated game.
Why should people not complain about class balance? With your logic people that play the latest retail patch should research and play PTR for a few hundred hours before they criticise the state of the game or even buy it in the first place.