The OP was using a shorthand expression for the oppression zones surrounding free speech zones. Free speech zones are areas where normal rights apply, implying that their immediate vicinities are special areas where free speech is curtailed. The zones themselves aren't oppressive, but indicate that oppression exists at their borders, and the free speech zones themselves are used to justify the oppression zones.

OK, I get that one could make that inference. And, having read more about them [1] I think I picked the wrong thing to rebut, as they are probably one of the better examples of "restrictions on expression." The others, I still contend, not so much.

[1] https://en.wikipedia.org/wiki/Free_speech_zone

"You may speak freely, but men with guns will escort you to a cage where you may do so in a place nobody can hear you"