A US Tiananmen-comparable example would be ChatGPT censoring George Floyd's death or killing of Native Americans, etc. ChatGPT doesn't censor these topics
Huh? TPTB in the US do not try to censor those topics; if anything they encourage discussion of them (or at least did until this year). US "AI" systems censor much the same topics as US social networks, just as Chinese "AI" systems censor much the same topics as Chinese social networks.