About the whole Castlevania vs Akumajou Dracula, I thought I remember an interview from a while ago where they mentioned they were switching back to Akumajou Dracula because the Japanese fans disliked the name being changed to Castlevania.
I don't think it has anything to do with Dracula being in the game or not. Plus, he was in HoD and AoS, through the Wraith and Soma in the bad ending, and they also specifically said Castlevania was Draculas Castle in those games. I don't think you can predict the villain based on the name of the game.