They are based on a stereotype that is inherently negative, which is pervasive in popular culture (especially in gothic horror like Dracula that inspired Strahd).You are right of course. I was just wondering, with all the baggage surrounding the Vistani, how far WotC would even be willing (or even able) to go. Can the Vistani play their usual role in Ravenloft without relying on negative stereotypes of the Romani? Can they play any role without relying on those stereotypes? I'm sure that it's possible. I'm very unsure how WotC is up for that task. Hell, I'm fairly certain I'm not up for that task, which why is I'm changing them the way that I am.
If I had a player of that heritage, I would certainly ask for their input before running the adventure. I would be prepared to not run it at all.
Their role as human minions of Strahd is important to that story. The fact that they're based on Romani culture is not important to the story.