Personally, I’ve never heard of anyone selling back to Disney directly, but I’ve been told directly by a guide that they do.
At a recent tour (May), in response to concerns I raised around resale restrictions on Riviera, the guide touted that Disney would buy contracts back... “depending on what demand for that property is at the time.”
Might have just been sales talk to counter the “devalued ownership” concerns. But he did mention Disney buying back directly.