How do you get to authoritarian, when it’s the Brazilian authorities demanding that people be silenced? Perhaps you’re referring to some unrelated situation where X has been censoring people?
Could it be because Steve Bannon is a personal friend of the Bolsonaro family?
Additionally, Musk complies prolifically with censorship requests when they come from racist fascists like Narendra Modi. The source for that is literally Twitter itself in its report on removal requests (the link is in this article): https://restofworld.org/2023/elon-musk-twitter-government-or... .
What's the difference? Well, Musk likes Modi and his vicious crackdown on Muslims, and he doesn't like Lula's government because he's a popular leftist. Like, you don't have to agree with either side to see that the only principle at play here is Musk's personal political grievances.