Let’s address the reality of the situation first. I am not interested in playing this stupid game where the private acts of private corporations suddenly become the acts of government.
A private content publisher is allowed to moderate the stuff they publish. Simon and Schuster rejecting my novel is not censorship. This principle includes highly permissive content publishers like Facebook and Twitter. I don’t think anyone here is seriously arguing that the Klan deserves a Facebook group. Obviously it’s well within Facebook’s rights as both an online business and a publicly-accessible service to kick the Klan out. So I am really not seeing what is so authoritarian about removing misinformation about public health - the only way your argument is even remotely defensible is if you wrap it up in a ridiculous thought experiment. And being banned from Facebook for posting conspiracy theories is no more Stalinist than being banned from Chuck-E-Cheese for booing Munich’s Make Believe Band.
To get to your actual point:
Shouting “fire!” in a crowded theater when there is no fire will land you in jail. Lying about the efficacy of your pharmaceutical company’s medications will (or should) land you in jail. And a successful libel/slander lawsuit can ruin you. Some of these legal issues are thorny and I have mixed feelings on them (until recently Canada has highly repressive libel laws). But certainly lying pharma executives who get people killed should go to jail. Certainly the guy who pranked the crowded theater should be held criminally liable for the resulting stampede. Free speech is not and had never been the same thing as freedom from consequences of speech.
If it’s just some guy ranting on the street then yes, congratulations, the state should leave him alone.