No, I would not. Freedom of speech pertains to legislation from congress preventing political speech. Most companies already prohibit employees from discussing salaries, under penalty of termination. Any business can ask you to leave, as a patron, for using profane speech in their establishment, or any number of other reasons. Please stop participating in this absurd and obnoxious fallacy wherein you decry anything you dislike as violating your "free speech"
> Freedom of speech pertains to legislation from congress preventing political speech.
Freedom of speech is broader than that. Freedom of speech not only extends beyond congress (which the Supreme Court has repeatedly affirmed), it also goes beyond political speech. You have the right to espouse openly racist beliefs. You have the right to espouse religious beliefs, and beliefs on the best way to grow corn, and what the best auto maker is. These are not political opinions except to the extent that they are protected from suppression by politicians. (Alternatively you can argue that basically all speech is in some fashion political, in which case the "political" distinction is meaningless.)
Retribution for discussing salaraies is a violation of federal labor relations guidelines. Companies can write that in their handbook but not enforce it. If they do, contact a lawyer and the national labor relations board.