If (and at this point I think it’s a pretty big “if”) WDW’s opening gets pushed, it would have to be the company’s call. Orange County has already said they are staying out of it, and there is no way DeSantis would ever try to stop them.
While they have already proven that they are willing to sort of do their own thing, I don’t see a world where WDW doesn’t reopen while Universal and SeaWorld continue to operate. There is already an “acceptable standard” for operating parks in Orlando, and that doesn’t seem to be going away.
That said, the point at which this really becomes irreversible is next week when parks CM’s start getting called back to work in order to gear up for operations.