I don't think Dragonmaw would become an Orc subrace. While they are visually distinct they are pretty much exclusively 'bad guys' right now. Mag'har Orcs and Black Rock Orcs would be more likely candidates for a subrace.
I agree that they will most likely be implemented as cash shop items, cosmetic skins are basically why the cash shop exists.
You just lost The Game
yeah, but the orcs have many options to choose from, besides you could always play a rebel faction who's still with the horde, or a bunch of loners, anyway, blackfrock orcs also have the same skin tones.