Disabling racials is a nerf and a lot of Horde players will quit without their racials on PvP arena. More casual part of the Horde may agree to, but only on HvH BGs, because they don’t want to face immunities and AoE CC.
I had alternative suggestion, but now that the Horde got all advantages (racial, numerical, queue time, premade organisation) they won’t bother with it