Considering that it has Unburden and his only viable Flying attack is Acrobatics, i guess they are still viable on Hawlucha.Even when the flying gem is released, is it even viable with the gem power nerf?
To clarify, gems are now 30% power, not 50%. See here:
http://www.smogon.com/forums/threads/pokémon-battle-mechanics-research.3489239/page-40