Today I received the Fire Hidden Appearance in Azsuna. I was completing the Leodrath's Kin WQ when a Nightborne Animator dropped it..
This is interesting to me... Having spent more than 20hrs since getting AK5 farming a combination of falanaar and moonguard mobs for the fire appearance I'm starting to suspect something else maybe a hidden factor (yes... i acknowledge randomness just bites sometimes, and that random is probably the only thing in my case).
Most of my farming time has not been while world quests were up in those areas, I actively avoid world quests with a lot of mob killing in any zone. i haven't bothered with most suramar WQs since I'm already exalted.
Reports I've seen for drops are all mobs attached to world quests (faldorei, mooguard soldiers), a blue post before most hit AK5 suggested something along the lines of 'keep doing world quests' (i am looking for the specific post, but as a corollary some other specs have drops that are linked to mobs while on world quests)
Also, in a group of mages farming at moon guard, it is more likely that someone in the group has a world quest involving the mobs (this feels like a weak link)
Most of these possibilities are easily ruled out by a single person getting the drop when that case doesn't hold, and I welcome this possibility being squashed by evidence. After all, I want to beleive that most of my time doing this has had a chance of something dropping, that it really is ONLY AK5 and random, and not that I've wasted so many hours.