I read TV-Tropes saying that classic 80's cartoon today is copyright by Disney, and the old D&D comics from the 80's by DC.
I guess CGI is easier to be produced than action-live action, and here the true goal is to promote the brand as a multimedia franchise. Ravenloft is perfect for an action-live horror movie for no fandom audence.
Forgotten Realms is the blue-eyed boy of D&D but not all eggs should be only in one basket. There are space for Greyhawk and others settings, even they can allow themself higher risks with lesser known settings.
And let's rebember a good story is really important for the success of the production.