I shouldn’t have said ‘planned fourth season’, but I’ve read that the 3rd wasn’t the planned ending until they were into production.

Lane Factor talks about not knowing it was ending until well into filming in this Vulture interview. He says that he knew the future of the show was uncertain. This Paulina Alexis interview also says that it was mid-production that they learned it was ending. Midway through filming they announced that they were writing it like it was the end even though it wasn’t certain that it was ending. She says the same thing here. It is weird though because Sterlin Harjo does frequently say that it was a creative decision to end it, yet it’s often referred to as cancelled. Even as a creative decision, it seems to have been a very late one.

Holy shit do I hope they do that Willie Jack spinoff she talks about in those interviews!