Yes, but the reason it worked for them was that the workplace has a culture of bad-mouthing, and there has never been a serious effort to transform that into a culture of respect.
No: in Canada and the USA "Freedom of Speech" applies to public speech, not to the workplace.
I don't just mean that in a facile way. I have spent a fair bit of time reading about rights of expression and communications, including discussing the points with lawyers. I have a personal interest in the topic, and it was also part of my job.
The only "Freedom of Speech" that applies in the workplace is that which is explicitly granted by the employer under some conditions, circumscribed by Civil Rights or Human Rights acts and Labor Codes or Labour Codes, and augmented only by any "whistleblower" or mandatory reporting legislation applicable to the situation.
If someone has an opinion that is inconsistant with the limits laid down by the employer and the applicable laws, then to the extent that the opinion does not reveal anything restricted by a confidentiality agreement or secrecy oath, the person may reveal the opinion in a public place or in a private dweeling where they have been permitted to reveal it -- but if they are in the workplace, then they must conform to any employment code and laws. Hereabouts, those laws include e.g., non-discrimination on any of the "Prohibitted Grounds" of the Canada Human Rights Act.
Bad-mouthing and denigration has no place in the workplace, not even in "private conversations". There is no right to express such things on the employer's time or on the employer's property.