Optimally the DPS now should use aggro-reducers (Diversion and Lucid Dreaming) as often as possible, especially RDM because it basically just chains high potency spells and oGCDs very fast right at the start of the fight.

Not saying that it's impossible to hold hate to a RDM who doesn't use aggro-reducers but tanks sacrifice DPS to use extra useless aggro combos, while DPS don't sacrifice anything to use aggro-reducers. So the priority is pretty obvious here in terms of efficiency.