This is how I feel about Darklords too. We're currently running a Ravenloft campaign with 3 DMs. As an example, if we take Strahd all 3 of us are going to portray him differently, use his powers and magic differently. Further, if he's destroyed and reforms who's to say his statblock doesnt change as well? I'd argue in favor that they would be changed in some way. So I understand why and it makes sense that stats werent included in VRGtR.