First, Ravenloft isn't the real world and doesn't have real world history. If you care that much about "history," then you should also remove every trace of magic and all non-human PC races, since they're not historically accurate.
Secondly, it's incorrect, because real-life people who have birth defects like kyphosis (the technical term for hunchback) are not magically cursed, no matter what some people in the real world may have believed. It's deeply insulting to say that they are--just like it's insulting to say that just because some people believe that actual Romani are all thieves with powers of divination and the evil eye, that the Vistani should all be like that. Actual, real people have deformities. Edit: They shouldn't be treated as magically cursed for it.
Thirdly, by your logic, why not make sexism, homophobia, and skin color-based racism an official part of the game? I mean, it used to be part of Ravenloft, because that was part of Falkovnia: Vlad Drakov had a disdain of women and "effete" men which he enforced throughout the entire country, and there was a higher Outcast Rating for humans that came from domains with darker skin colors. Are you upset they removed that as well?
And fourth, if you really cared about what people believed and wanted the stats to reflect that, you'd better throw out the entire Monster Manual. "Historically," there was really no difference between demons, undead, and lycanthropes. And fey.
And finally, fifth, "historical reasons" are an incredibly stupid reason to keep something around.