I appreciate your providing context for what they're afraid of. But I find DeSantis and company attempting to capitalize on that fear before this company has even taken possession of the stations to be pandering.
That aside, what can be done about it? If they're legally approved to buy these stations and make format changes, they'll have to deal with the PR and financial fallout or reward of it. And in a free market, another Miami operator can pick up the talent and serve the conservative audience. Isn't the usual argument "let the market decide?" If the exile audience is loyal and profitable then a struggling station in the market would be wise to serve that audience should the new owners abandon them.
These protests have happened with the loss of college eclectic formats, classical, and religious stations. Each interest group decrying the loss of something essential, important or irreplaceable. Each group equally passionate. And every one of them moved on and found something else, because the FCC does not regulate formats.