Nothing you mentioned has any relevance to an employer firing an employee and rehiring them as a contractor, which is perfectly legal in the US. This actually

Nothing you mentioned has any relevance to an employer firing an employee and rehiring them as a contractor, which is perfectly legal in the US. This actually happened a lot after the ACA/Obamacare law went in effect a decade ago. Many employers were faced with the mandate to provide insurance for full-time employees and decided to fire/downsize those roles and hire independent contractors in their place (which did not need to have healthcare provided by the employer).