IsFlyableArea() returns true when player can't fly
 

It was a struggle to get this fixed in WoD (it wasn't fixed until late in the expansion) and I assumed it'd be on a checklist to get fixed in Legion so hadn't said anything, but just in case it's slipped under the radar:

IsFlyableArea() (and by extension [flyable]) returns true if the player cannot fly in the new Legion zones. While it may be true that the zone is flagged as a flying zone when the player eventually unlocks flying, the only purpose of this condition seems to be whether the player can fly.

For Livestock, I check IsFlyableArea() and the various spells that are learned when flying is unlocked. That's the only way I've found that works all the time.

Actually this looks to have been fixed in the past week. :D

IsFlyableArea() is returning false is new Dalaran and Suramar.

Thanks Blizzard for fixing this!