Lawsuits may fly, but I'm doubtful any would really be successful. There's very little worker protections in the US. Legal structures and courts often take a corporation's side against workers, and there's very little legal protection or recourse that employees can take against their employer. This is all by design too. This will fall under the fact that companies can create nearly any requirements or policies for their own employees as long as they are not discriminatory against a protected class.