Sure, I never said that concept doesn't exist outside of government. Just that there is no right to it anywhere except given through government mandate and on governments behalf.
The original statement was
Free speech for me but not for thee.
Which implies that the worker has a right to "free speech" at work but is abused by some other class of person making up bullshit rules... which they don't. Instead it's a right that granted by the Government for public (actually public) functions. Further it's not a bullshit rule since it's a rule that was agreed upon when the worker joined the company... And I would be willing to bet that the management (or other class that is under the "thee" reference) themselves adhere to as well. Especially since it went to court and was found to be applied equally across the board.
There is a reason I quoted "right" in that post you know... Or did you skip that to make a pedantic argument?