Are you sure because i remember a few episodes into the second season kenny powers said on Facebook that they signed up to make a 3rd and 4th
I have always heard that 3 seasons would be it for the series. Here is what Danny McBride and Jody Hill said about it:
"We've always imagined this thing as something that we would keep short and not give it a chance to kind of get old," he explains. "We have really approached each season as if it was just an act of a larger story, and so the third season to us has always been the climax of the story."
McBride and co-creator Jody Hill admit that they already know how the story of Kenny Powers will end, and McBride even hints that said ending may be closer than we think.
Both acknowledge they have treated each season as "a long movie" and when asked if season three would bring the ending of the story, McBride responds, "Probably. Yeah, I think so."