Correct, as long as they’re government entities or exist at the pleasure of government (e.g. common carriers). “Owners of property that allow the general public to pass” is a trickier situation, usually implying a thoroughfare that might under other circumstances be considered a municipal street; shopping malls, including outdoor ones, usually do not allow political protests on their premises.
In any case, that’s not applicable in this situation. If the government had shown up in the form of the police here the First Amendment would have been the last thing on their minds.
