I'm so damn annoyed I can't reply to that blue post on the official WoW forums... I know they don't read them but I'm really angry about these bonuses. They're close to useless.
Why remove the XP bonuses? They want veteran players to level from 0 once again?
Because as far as I know, and as the blue said, these bonuses were to aid people who already leveled a character and wants to spend less time leveling the next time.
They should have just restricted the amount of alts you need at max level before the XP bonuses were applied again. To like 3 or 4.