Replace Tienanmen with discussions of Palestine, and you get the same censorship in US models.
Our governments aren’t as different as they would like to pretend. The media in both countries is controlled by a government-integrated media oligarchy. The US is just a little more gentle with its censorship. China will lock you up for expressing certain views online. The US makes sure all prominent social media sites will either ban you or severely throttle the spread of your posts if you post any political wrongthink.
The US is ultimately just better at hiding its censorship.
It reminds me one of Asimov’s robots trying to reason a way around the Three Laws.