Just adding my experience to the thread. On my Druid I have a polearm that I normal have transmoged into one of the Claws of Ursoc. Today that appeared to be removed. When I when to change it I could not apply the Claws to my weapon.
I attempted to transmog a random staff and that worked. I also was able to transmog to one of the Legion Artifact Weapons themselves (Scythe of Elune) in the staff category, but the Claws of Ursoc under the Legion Artifact option does not work. I have not tried any other combinations, but it seems like the items in the Legion Artifact area no longer ignore the weapon restrictions (allows fist over a polearm in my case).