appears to be bugged heroic dungeons are not counting at the moment
i just completed a Heroic Siege of Boralus and it did not count.
Seems that only TWW dungeons are counting and not the older dungeons currently in the mix when random queuing
Well that's at least some reward for my continued farming of Priory for the damn enchant drops.
Appears bugged, Random Heroics only count if they are the new TWW dungeons, doesn't count if you complete the old dungeons from previous expansions that have been brought it. Will probably get fixed in the first 24hours
Only TWW Heroic dungeons are counting towards the quest. M+ is working just fine.