If kooks don't have the freedom of speech, then neither does anyone else.
Youtube was and is taking down videos from respected, hitherto unimpeachable medical doctors for saying things that didn't fit the Leftist narratives.
Actually, they were giving medical advice well outside their area of specialization, meaning that they were using their medical credentials as their authority to push bad information.
This happens all the time in popular discourse. A distinguished professor in one field will make a claim about something in another field and those who hear what they want to hear will accept an unqualified viewpoint based on the false authority of the professor.
For instance, Dr. Richard Dawkins is a world-class biologist, but he doesn't know beans about theology, philosophy, or what Christianity claims and teaches. But he makes claims against Christianity based upon his reputation in biology. Many people accept what he says, simply because he is an expert in biology.