It's a west coast California Ideology thing. You'll find it by name at SlateStarCodex, part of the LessWrong brand "rationalist" cultists. They're not hard to find but I can link them to you if I must. That's where you will find self-described luminaries like Eliezer Yudkowsky that do call themselves autodidacts, their word choice. The gimmick is that their grand high cult leader never completed high school and states that all academia is bunk because it doesn't agree with his ideas, which come from a bad interpretation of Harry Potter movies and then he made a massive fanfiction out of them (he admitted once that he didn't bother reading the fucking books all the while) and somehow that made him a self-described "AI expert" among other things to the billionaire-subsidized cult that he started, later telling computer scientists how computers work (and neurologists how the human brain works too, because why not).

You'll also find other examples of self-described autodidacts here. https://hexbear.net/c/sneerclub@awful.systems

Warning: this is a painful viewing. The host is very patient. https://www.youtube.com/watch?v=hxsAuxswOvM

Not necessarily by name, but Jordan Peterson does the "expert on communism without actually fucking reading anything from communists" thing, which is the same deal.

Same with Ben "facts don't care about your feelings" Shapiro, who isn't really qualified to speak on much at all, but speaks as an authority to rubes.