Now whether such agreements, entered into by the government, are constitutional is a complicated question. Private parties often do enter into various confidentiality and nondisparagement agreements, and they’re generally enforceable. (See, e.g., Cohen v. Cowles Media Co. (1991).) The government is subject to First Amendment constraints, even when it’s acting as contractor; and I’m inclined to think that such a nondisparagement agreement, aimed solely at preventing embarrassment to the employer (rather than, say, preserving client privacy or national security secrets), is unconstitutional. Still, it’s not completely clear what the rules are here.
What troubles me more, though, is the political accountability question. Whether or not such agreements violate the First Amendment, should an executive agency really be trying to restrict its former employees from complaining about the agency to Congress, or to the public at large?
Say you were on the board of directors of a company, and you learned that mid-level managers were making financial deals with ex-employees, under which the ex-employees were forbidden from “making any . . . negative comments” to you about what the managers were doing. Would you be happy about that?