Really? I would say that varies from one restaurant to another.
An employee's job is to do what the employer decides needs to be done, at a mutually agreed rate of compensation. If the details of the job change, and if either party no longer finds the arrangement satisfactory, it's time to change jobs. I do not patronize restaurants that feature skimpy outfits as their primary attraction, but the place is private property, and it is the owner's place to make employment decisions - and the employee's role to decide whether to accept those decisions or move on. I agree with you morally, but a court is not the place to regulate moral conduct. Legally, this should not be a question subject to government interference. I'd say the same thing if my daughters had quit or been fired from a job working for a dog like this guy. She's moved on. It's over.