“Post-“ originally is a temporal signifier. It means “after.” Post-left anarchism, whatever it means, refers to an anarchism which has, by and large, come after, and largely out of, anarcho-leftism.[6] In my case, I was receptive to exactly the influences which Jason McQuinn mentions. When I use the phrase (I don’t use it a lot), I think of anarchists writing in the last 40 or 50 years who have taken up, or taken on, matters which the traditional anarcho-leftists never considered; or if they occasionally did consider them, their reactions – variously stereotyped, superficial, mocking, and dismissive — called for critique.

https://theanarchistlibrary.org/library/bob-black-notes-on-post-left-anarchism