Kit foxes aren’t rare. There is no end to the number of projects they’ve shut down in the Bakersfield area. Tey are everywhere in abundance here.
Seems these “endangered” critters are strangely bent on making themselves virtual household animals. Older societies would likely have accommodated this, and we’d start to see pet foxes.
As for rare species becoming pets... this is probably precedented by the domestic cat. There isn’t any wild species that, like the wolf does to the dog, can claim to share a species with the domestic cat. This means that the domestic cat managed to get itself off of some hypothetical ancient endangered list by making itself a household pet. But there were no biologists hovering over society to make a stink about it either.