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 afoul 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.