It would have taken a major re-working of the story of the second and third games in the series for that to work, since Lords of Shadow 2 it set up by the epilogue in the first game.
But if Konami had just released a game where you play as Dracula in an alliance of necessity with Death, trying to keep Satan from coming to earth so Draculas rule could remain absolute then who knows how it would have done. I think there would have definitely been potential there, especially if Dracula used the shadow whip as his main weapon, people would be wondering why Dracula was using a whip. And I'm sure if Konami said the next couple of games will focus on who this Dracula is, then it would have been seen a mile away as that this vampire calling himself Dracula was at one point a Belmont.
But fan theories aside, they could then have had the second game, Mirror of Fate just follow Belmonts trying to kill Dracula through the ages, I think a game with more than two of them would be better and each chapter you play as the Belmont that came before you ending in Trevor who wants to kill Dracula for the murder of his parents Gabriel and Marie
And then you release Lords of Shadow 1 but switch the Necromancer and Vampire areas so the castle is last and they could try as hard as possible to keep the fact that the lord of the vampires is carmilla under wraps so the whole game you expect to be heading to Dracula, but then surprise, you're fighting Carmilla and then have some kind of proper chapter detailing Gabriels transformation and better reason for him to end up despising the Brotherhood and humanity.