I'm sure he's removed accounts hypocritically, but I just searched for John Brown Gun Club and got like 50 chapters. So if he did remove it in 2022 it caused a Streisand effect. The people in the second link were all reinstated and it was declared a mistake.
He can do whatever he wants, but it's pretty obvious that Elon Musk does not care about free speech and only wants people like this guy on the website because he personally agrees with him. There's little plausible deniability anymore. I'd be shocked if Elon Musk didn't believe outright that the Jews are controlling the world and attempting to manipulate fertility rates to ensure a majority-minority west. Just look at what he says, who he associates with, what he highlights on social media, and tell me with a straight face that free speech is his primary concern right now.
I've seen pretty convincing arguments that Elon's brain was completely cooked by:
1) his wife leaving him - attracted him to manosphere/red pill stuff and
2) having a trans child he doesn't accept
These personal life items turned him fully to the alt-right.
You are correct. It's pretty clear he wanted to turn Twitter into a massive echo chamber to air his pathetic grievances.
I've seen this happen to completely normal people. I know a guy personally who has turned into a Timothy McVeigh type purely from listening to the Joe Rogan podcast over the past couple years. It's sad to see.
Oh that happens too. "Marxist" doesn't really mean much but a significant portion of the "tankie" livestream audience consists of former alt-righters.
As for the theory, I think it's just voluntary brainwashing. These people will go to work and play seven or eight hours of repetitive political content directly into their ears every single day. A lot of these people need it just to function. They can't handle silence anymore. I know people who used to love reading or video games or exercise, or whatever, and they've replaced it with podcasts or YouTube videos. This can continue for years. Years of listening to several hours of people telling you the same thing over and over. Of course these people go crazy.