So, I was doing some research and found some interesting things.
I am going to start by saying that i'm not a lawyer. This is not legal advice. This is just some interesting things i've found in researching force majeure.
So, my understanding is that since (before this COVID stuff started) David's rental contracts did not have a Force Majeure clause the contracts would fall to one of two possibilities: Frustration of Purpose or the Doctrine of Impossibility.
Some sources:
https://en.wikipedia.org/wiki/Force_majeurehttps://en.wikipedia.org/wiki/Frustration_of_purposehttps://en.wikipedia.org/wiki/Impossibility
Okay. Things are probably very strange here. A court and a bunch of high-priced lawyers will actually have to figure out what's going on. But i'm offering a legal thought experiment.
In order for Force Majeure to apply, the contracts would have to have explicit Force Majeure clauses in them. They don't, so we then move on to Frustration of Purpose or the Doctrine of Impossibility.
According to the wikipedia article on Frustration of purpose, it applies when the reasonably known purpose of a contract can no longer be fulfilled...but the specific terms of the contract CAN still be fulfilled. To put this in DVC terms: The reasonably known purpose of the contract to rent DVC points is that the family wanted to enjoy a Disney Vacation. If the parks had closed, but the resorts had stayed open, then this would fall in to the "frustration of purpose" bucket.
The Doctrine of Impossibility applies when it is impossible to fulfill the obligations of the contract. In this case, Disney, the government, etc. have closed the resorts and it is literally impossible to have a reservation that the renter can check in to. It is impossible to perform the duties specified in the contract.
In the doctrine of impossibility, everyone is excused from all of their duties. The DVC member is excused from their duty to provide the reservation. David's is excused from their duty to pay David's. The renter is excused from their duty to pay David's.
Once thing that I thought was interesting from the article on the Doctrine of Impossibility though:
Based on that, I am theorizing that everyone owes everyone there money back. I believe, from a legal perspective, the DVC Member owes David his money back, and David owes the renter their money back. Essentially, everything is undone as if the contract were never signed.