Searched for AA-related topics in the official forums, didn't see any mention of a bug so I apologize if this thread has come up already.
Ran it twice in the same group today for both Normal/Hard Mode. The Celestial Mage does not come down from her platform to fight the group but instead stays up there. Axes do not spawn, Atros do spawn and AOEs still occur. Mirror Images are notably absent as well. Loot stays up with the Celestial Mage after death as well.