It conflates the principle free speech with a narrow legal reading of the first amendment. Whether on purpose, or accident, I cannot say. The alt-text is also only illuminating in the sense that the CCP might heartily agree with it as well, as they see their crusade against free speech as nothing more than maintaining the public order and peace. In publishing the comic and leaving it up, Munroe has done more to damage the principle of free speech in the West than any opinion article I can think of, because it chains together several fallacies in a clever and funny way.
A comic response to xkcd - https://sealedabstract.com/rants/re-xkcd-1357-free-speech/in...
A legal rebuttal to anybody thinking AWS’s actions were legal (they were not, and hopefully a judge will agree soon) - https://cdn.pacermonitor.com/pdfserver/SGS7Z4Y/137165184/Par...