I'll be straight up. I'm not really convinced about the stated reasons here. If Lords really did as well as they say, it's only smart business to continue with a successful trend. I'm personally of the belief that Dave Cox doesn't want to work on Castlevania because he's tired of getting (justifiably) crapped on by fans and others for the strange aesthetic of his game. He has come across as rather defensive and frustrated at times, talking about how reviewers don't know what they're talking about, or something like that. I'm also personally of the belief that Konami doesn't want to continue any further down this road for the same reason, and possibly because Lords of Shadow wasn't the smash success that they might have hoped it to be. Therefore, I think he's being allowed to wrap up his stuff and then being sent down the road. I have a strong hunch that, say, ten years from now, Lords will be known in history as the Castlevania that wasn't Castlevania, but that some people still like anyway. Not the thing that saved the Castlevania series.
You can call me cynical and pessimistic, but I'm only using common sense here. If Lords was received really, really well, we'd see a heck of a lot more of its ilk. History and common sense says so : p