I really don't see how they're going to do this. Fitch basically said that the only viable solution is to reconstitute the district, maybe with a different administrative structure, but with all the powers and rights that it had before.
Now, DeSantis could try to put in a district that has administration from the counties or from the state as opposed to the Disney elected administrators, but that would run a foul of the homestead guarantee in the Florida Constitution.
I don't see a way out for DeSantis at this point or even some face saving measure. His choices are to basically repeal the dissolution, or tank the Florida economy.