Priest, Hunter and Shaman quests should also fall to Tier 3, if not 4. You may still find some Ress Priests at very low levels, but Gala or Highlander Priest are the archetypes to go for the class. Shaman is dead (the same reason to also demote Vessina) and no one is also playing Quest Hunter. Amet as well should drop to 3. It's not played even in HL Priest.P
Believe it or not, the Warlock Quest is all the rage right now in Grandmasters and high legend with a build including both Alexes and Malygos to OTK. At the very least it's a Tier 2 card now, with potential to be 1.
These are all pretty good comments but I've seen a lot of Quest Priests on the ladder recently, I think it should stay were it is. Agree with the rest however.