As I said, nothing about the setting or any of the adventures set there has ever appealed to me, and I know basically nothing more about the 5E adventure than I've picked up here and there online.Well, if you start off on the assumption that everyone in Ravenloft is a villain, you’ll only be disappointed a couple of times.
Surely though what makes a villain, a villain is what they do, not the label the DM puts on them in advance. If the dusk elves behave villainously then surely they become villains. There are plenty in the book for them to join.