So... I've just noticed for the first time that I was taking nonsense damage. A quick look at the combat log tells me that the new Raid Boss has an aura called "Chilling Aura", which pulses damage onto players every 3 seconds. I learned later that more bosses apparently have this unlabeled mechanic.
So my question is... why? Why is this a thing? You wanted to promote off meta team comps. But this kitten here basically means you either need to bring healing power on everyone to make any self regen worth a kitten. Or always have Druids speced for healing with you. Heck, this even strongly cements the stacking meta.