This story is part of a new lore continuity, so besides being heavily thematically related, and featuring similar characters, it has nothing in common story wise with the old castlevania games.
In this story, Gabriel does become dracula, but the exact means by which this happens is unknown. People theorized that he has ascended, and Dracula is his shadow, people have said that the powers from the first two lords of shadow have corrupted him over time, people have said that God has granted him immortality against his wishes, leading to eventual corruption.
DLC has been announced. Though whether or nor it will solve this question is unknown.
--- "Archangel's identity is hidden about as well as my ex-girlfriend's *****."
Probably not going to spell the last name right but Gabriel is rumored to be the bastard child of the Cronqvist(sp?) family.
Mathias was part of this family in Lament of Innocence. We know Mathias becomes Dracula. What makes me sad is they never released a direct sequel with Leon going after Mathias aka Dracula. If not a 3D game, then a 2D Metroidvania. :(
Yeah, this Castlevania actually feature no real Belmont . Gabriel here is just taking the name of Belmont himself and there is a chance he might be a scion of Croqvist family.
This Castelvania shows a new concept. Rather than Belmont vs Dracula, they make the story like "Dracula vs Satan". I like this. Dracula toppled the prince of darkness himself and become a new prince of darkness. He earned the title "Lord of Darkness" fair and square this time, not like self-proclaimed in other games.
I have always wonder when Dracula said he is the incarnation of evil in other Castlevania games; "Really? Then what the hell other the powerful demons, like Lucifer,are doing ?". Now this game explained it. Dracula beats the crap outta Lucy and he become the incarnation of evil fair and square. He even befriended with the Death himself. Nice? --- Duh...