As I noted on the related posting, it was lucky that the Commissars of Free Speech were there to protect everyone from this dangerous counterrevolutionary. Uncontrollable theism might have broken out! (/sarcasm off)
Freedom of speech doesn't mean you get a free microphone to use.
Imagine if the valedictorian talked about Che or some other person, or invoked Wiccan. That's be perfectly acceptable.