World of Warcraft: Legion remains in development. Before I logged in last evening to raid, I watched FinalbossTV do a test raid, so those developers are indeed hard at work on this expansion and soliciting feedback from testers on all the things.
One of them is the revisions to Professions, especially after the gutting they took in Warlords of Draenor. The proposed revisions return significant depth, and grind, to the Profession subsystem but also continue with certain discovery proc mechanics that made the Warlords version tolerable and enable them as catch-up friendly systems for returning players or characters long neglected. (The reason for the catch-up is to keep players in the relevant content and not in the obsolete stuff, so you can play with friends faster.)
Bellular Gaming has a good video on this, which I embed below: