Ah, so Musk must have X systematically taking down calls for public execution of his political enemies, then? This is a legit exception to free speech absolutism and he is just asking Reddit to do the same thing he does on his platform.
It's illegal to call for violence against others. It's also illegal to call for a violent attack against the government.
Calling for public execution on social media would have you banned under any administration except for the early days of the internet.