Livre d'Or

I think the thing about Buffy being progressive for its time is that it's time is half 90s, and half... I don't know 30s. Whedon has taken lots of old stories that he loves, and has noticed that they're sexist and so (not always wholly successfully) tried to subvert that, while staying true to other aspects he loves.
Unfortunately, for whatever reason, he hasn't addressed the racism that's in those stories, either on the level of detail or what the structure of those stories is saying.
I don't agree with Joss's decision to use a gypsy curse, but I think that it's there because it's a standard trope and in keeping with the B-movie aesthetic.

A broader thing is that Sunnydale is very white (it's set in California and my understanding is there are a lot more Hispanic people there than we ever see on screen), and a lot of the plot lines seem to be about protecting this exaggerated white-picket fence America from outside threats. Threats which more than a few times (I think especially in the early seasons) are connected to the racially other.
That makes me kind of uncomfortable (to say the least!) but I think that I can see how his aesthetic led to it.

Tl;dr: Joss Whedon is a puppy, yay to feminist retelling, but not examining stories for race-fail inevitably leads to repeating it.