JEB
Legend
I don't see any reason why you can't have both. If old details about the setting are a problem for modern play, there are many creative ways of dealing with them that don't require a hard reset. Just look at how Marvel Comics has handled its canon for over 80 years. (warning, TV Tropes link)I know this sounds insane to many of you, but I value setting consistency over raw playability.
Interestingly, at least one creator who worked on 5E Ravenloft - Strix, who worked on Valachan - outright said she wrote her domain as a continuation of the old lore. (Considering some of the other Easter eggs in the book, I wonder if an earlier draft of 5E Ravenloft had been more continuation than reboot.)