A11N is one of the first instances where a healer has to handle a decently tight healer check that will result in a DPS dying outside of Savage and Trial EX content. This is gonna jam up a lot of healers if they don't realize what's going on and at this point there are probably going to be a lot of healers who are either new or alts that don't realize what the Prey mechanic does in the fight. It should probably be noted at the start of A11N that the DPS with Prey will need to spread out and get ready to be healed out the ying-yang to survive.

Also, please do not blame poor performance of a healer on DPS / Cleric Stance. It's a method to optimize as a healer and the pinnacle of healer performance is making full use of their tool kit in an optimal manner.