I think you call his bluff, play chicken with him. See what he comes up with as his terms to the agreement, read the contract, have lawyers check it for loopholes and it they find one, sign the deal and exploit it.
Then donate the money to another foundation.
At some point I’d be willing to bet he would back down and not follow through, but anybody that is in a position to call him on his bullshit should do it
Work at a dishwasher factory. We used to make a model with windows, they were really expensive parts, which meant that they were really expensive dishwashers for a feature that really isn’t useful.
It makes sense in a microwave or oven because you can check in and make sure it’s all good, or pull it out if it’s done. You can’t do that with a dishwasher, it just runs it’s course.
Plus all you could see in the thing was splashing soap water.