What makes a law in Florida constitutional? Presumably, it's constitutional if it's passed by both houses of legislation and signed by the governor.
There are over 1000 special districts in Florida. I suspect many required their own legislation. The Florida constitution references general laws and special laws, and includes the following definition:
(g) “Special law” means a special or local law.
It's been a while since I last looked but as I recall, a charter typically is written when the legislature creates a special district. (I believe this was the case for the original RCID charter.) The special district's charter specifies how the board of supervisors are elected/appointed.
One special district's charter does not need to be the same as another special district's charter. Presumably, the Florida legislature is drafting a special law that is specific to the district that is replacing RCID.
As I mentioned before, I think the Florida constitution allows laws to be passed to create special districts, and to transfer the powers of one special district to another. I'm hoping someone else finds a section in the Florida constitution that limits this power. If not, then I think
this aspect of what's happening is legal from the perspective of the Florida constitution.
I think Disney's better play is to seek redress on Freedom of Speech grounds. Legal precedent is complex but the core argument is simple. Disney said something the governor didn't like. The governor retaliated in an attempt to "chill" Disney's protected free speech rights. ("Chill" is a word frequently found in a lot of free speech Supreme Court rulings.) The governor violated Disney's free speech rights.