It actually has no chance of costing them additional money, the issue will be that if Florida continues on its stupid (and wildly illegal) plan would be that Florida taxpayers end up on the hook for a billion dollar debt + taking over all of the servicing for the area around the Disney park (which will end up costing the taxpayers of Florida hundreds of millions of dollars a year).
But even *IF* they had to eat that billion dollars, it still would make business sense for Disney to be more inclusive as a company, since their customer base (and the world in general) is rapidly becoming more inclusive on the whole. The smart business decision for Disney is to do things that are popular with the majority of their customers, which in 2022 is, to use a trite and stupid expression, "going woke".
A billion dollars (which, again, they will not be paying) is toilet paper to Disney.