Actually, a few years ago they were renovating them. We could see the work while taking a boat ride from OKW down toward PO. They had stripped a number of them down to the bare framing lumber. A year later, when we went they were still at it. My DH asked the bartender at OKW what the plans for them were and was told they were being used as housing for people in the WDW college programs and some other programs where people come down for weeks to months at a time.
We were at OKW in March and rented a boat for a ride again. We didn't see any people in/around the treehouses, but did see lights on in some of them.