The amount of misunderstanding here is unbelievable.
A few things to start. Reedy Creek Improvement District was not Disney's private government. It was the local government, created by the state, where the landowner's get to vote on the governing body. Reedy Creek perfromed the normal functions of the county government. What this did was prevent Orange and Osceola counties from having to pay for this high bill through their taxes. Disney did not get tax breaks, they had higher taxes due to being the majority landowner.
What this bill has done, is remove Disney's voice in their local government by removing their ability to vote for the RCID Board of Supervisors. This would be no different than if DeSantis had said that he was no longer going to allow the residents of Orange County vote for their Board of County Commissioners and he was just going to appoint them. Every resident of Orange County would be out their protesting.
This is litterally taxation without representation. Because, Disney used their First Amendment guaranteed right of free speech.