Bob Black wrote Anarchy after Leftism, and that’s one way of contextualizing Hakim Bey as well. “Post-liberalism” exists in theology iirc but “Post-Leftist” as far as I know has always been associated in the literature with anarchy. National Anarchy is anther branch in that circle that’s interesting, too.
The last couple of years, I’ve heard it thrown around a lot more than usual, to describe like Tulsi/Greenwald/RT/Red Scare circles, but these people are all actually still Leftists, just Leftists who think the Russia stuff is retarded.