Am I misreading this or is Butler saying that GC feminism is fascist?
I think she's probably actually saying that, yes, though she conflates right-wing and feminist opponents (also, somehow: capitalism as a whole and French neoliberals specifically, because: sure!) when she says it.
But then, I mean, it's Judith Butler. A.k.a. "person who made a whole career out of never being able to actually say anything with any amount of clarity".
Point in case: JB saying what I think could mean "I'm an enbie" (but clearly not saying that ...):
When I wrote Gender Trouble, there was no category for “nonbinary” – but now I don’t see how I cannot be in that category.