Physically, the Treehouses are still there. They were a part of the Disney Institute resort before that shut down a year or two ago. Disney has torn down the townhouses and the club lake villas to build a new DVC resort, Saratoga Springs. The fairway villas and the treehouse villas are still standing, but Disney isn't renting them anymore. There is still a question what they will do with them. The Treehouses are standing on ground which is now protected, so if they are torn down, nothing will be able to be built there to replace them from what I have heard.
I stayed in the Treehouses and the townhouses in the 80s when I would go with my family . They were really kind of neat. Stopped staying there when we joined the DVC in 1992.