Musk is confused and ignorant. He is in fact omitting civilization from the discussion. Free speech is not unlimited nor absolute and never has been. The U.S. Bill of Rights is not absolute either. The Bill of Rights can be overridden by an even more fundamental concept of civilization: You do not have the right to endanger or harm your fellow citizens.
If freedom of expression was absolute then I could go murder someone and claim, "He needed killing. I was just expressing myself." In a civilized society I cannot do that, QED.
@laughingriver Yeah. Something about hubris, something, something...