> Amazon’s external communications policy prohibits employees from commenting publicly on its business without corporate justification and approval from executives. Herdener previously said the policy did not allow employees to “publicly disparage or misrepresent the company.”
Amazon is straight up firing these people for expressing their personal opinions. Amazon isn't even claiming they lied, or pretend to speak officially, or any other reason.
I am not a lawyer nor am I condoning this, but them is the facts.
edit: added play
It's pretty easy to come up with a lot of absurd and "legal" at-will policies (e.g. we'll fire anybody who watches porn)
My favorite which would work in much of the US is "We'll fire anybody who registers with the Republican party." (Or Democratic, if you prefer.) Especially in a state where registration is required in order to participate in the primary. It is legal, but, I believe, completely unacceptable to just about everyone.