I don't recall seeing anything mentioned on this in patch notes or anything, but something I've noticed tonight while raiding is that if I see the raid is wiping and can find a healer in a clear spot, I usually brez them with the idea that they'll accept after the boss resets and then they can rez others for recovery. However, once the boss resets, the option to take the brez disappears.
Is this something that's new? I could have sworn that I've read about others doing this, and I've even done this before in order to recover from a wipe.
I hope that made sense....I'm extremely tired right now.