Ed Greenwood put his two cents in, although honestly I don't think he should have had to, considering how well established even the basics mechanics of divine magic are in the Realms. That should be good enough for anyone, though I guess not Larian.
Anyways, unless it's been renegotiated, one of the supposed aspects of his (strange) contract with WoTC is that anything he says is canon, is canon unless WoTC explicitly says otherwise.
Note that he's very careful with his phrasing in that excerpt to not contradict the SCAG, but the message is clear-you need a divine patron(ess) for divine magic.
Again, I'm just hoping for some modders to bring back some of the flavor to the class, because this is probably the biggest disappointment of EA for me.
