We cant retcon the whip thing entirely- or we'd have to retcon Bloodlines.
And that would be a crime.
I'd never retcon Bloodlines, but after Bloodlines, I'd say that John Morris gave the whip back to the Belmonts, who'd start getting back into the family business, and generation to generation, eventually gave birth to Julius(who I'd keep, because he's still pretty badass). There'd also be no Jonathan Morris, nor PoR in my ideal canon. I WOULD, though, focus more on what the Morris family did after they initially inherited the VK, and I WOULD reinstate Sonia back into the canon, but via a different game. I still like my idea of having her as the blood link to the Morris clan(she marries a man with the Morris surname). Prior to that, I'd have her in a game/story where she's the older sister to the male Belmont heir, some tension between her and her family because they chose her little brother as heir over her, while a dark force appears yet the true heir is too young to wield the VK, so she takes it into her own hands, against her family's wishes, and like a badass, goes out to face it in a maverick-type fashion(which I always thought felt well for the Morris clan, who eventually become Texan cowboy-types before the events of Stoker's Dracula).
As for when the Belmonts give the whip to the Morris family, I thought of a means where it was possible. Richter, who's now maybe in his thirties(early 1800s), is lured back to Dracula's Castle when his children are taken by a group vampires(Dracula sympathists and loyal servents), and he goes there with a Morris(who's his vampire hunting pupil, so to speak). Eventually something happens where the Belmont blood is fobidden to touch the VK, and the only way the curse can be lifted in through an act of generational purification, which means, like, in 100, through sacred rituals, finally the curse will be lifted(which the vampires are aware of, but believe it would be too late considering Dracula to resurrect sometimes prior to the events of Stoker's novel, and there'd be no Belmont to silence him, as they'd be unaware fo the Morris clan). But, the curse is only on the descendants of Richter and his children, meaning those BEFORE(who are linked by blood) could still wield it, and Richter hands over the VK to his pupil at the end for safe keeping until the Belmont family could once again wield it.
I also had an idea of more Elizabeth Bartley. I'd still keep Mathias as Dracula(as well as the events of LoI), but prior to it, have Elizabeth as a child, the child of Mathias's sister, whom he used to spoil as a child(she was his favorite niece). After Mathias became a vampire, years after living in various areas, he returned to Elizabeth's castle, her now being a beautiful young woman(yet vain and evil), and stays with her for a while and turns her into a vampire.
I ramble on too much. I love fanfic sometimes and the possiblities!