Yes, but (IANAL) if the employee suspects that there was an illegal reason behind it, they can probably sue and subpoena documents revealing management motivati

Yes, but (IANAL) if the employee suspects that there was an illegal reason behind it, they can probably sue and subpoena documents revealing management motivations. Like, sure, a manager could wake up and just fire you because they were grumpy. But if it is discovered that there was internal communications about their political opinions leading up to it, then there would be a case.