“Then, in the American context, preventing others from speaking either with violence or a heckler’s veto does not destroy the concept of free speech as long as the violence/heckling is not governmental.”
That depends. Public colleges and universities, where many of these suppressions have occurred, are the equivalent of government entities and so must protect all free speech without regard to content.
“The First Amendment to the Constitution protects speech no matter how offensive its content. Restrictions on speech by public colleges and universities amount to government censorship, in violation of the Constitution. Such restrictions deprive students of their right to invite speech they wish to hear, debate speech with which they disagree, and protest speech they find bigoted or offensive. An open society depends on liberal education, and the whole enterprise of liberal education is founded on the principle of free speech.”https://www.aclu.org/other/speech-campus
My point again is that MW runs articles decrying the suppression of pro-Palestinian speech in the US, but also appears comfortable with the call for suppression of speech that runs counter to that. The principle here is not the protection of free speech, but rather the protection of only ‘approved’ speech. That position is certainly within the rights of MW, but then stop whining when others take the opposite position. If your comfortable with the suppression of your opponents rights, don’t be surprised when they return the favor. Personally, I don’t think any speech that doesn’t call for imminent violence should be suppressed.