I downed him on my sent in a PuG before the push off stage months ago, I don't think they've changed anything just most are now going above the DPS threshold for that fight.
They should add some bonus loot to his body if you can DPS him before he becomes invulnerable, like a new pet or something.
pet or mount would be nice.
no they haven't changed anything in that fight that i know of. that one they did change the quest update mechanic where now if you died before he was pushed off you could still come in and loot before getting locked out. before you were out of luck if you couldn't be rezed which happened if knocked off.