How is that an example of censorship?

Because it is not allowed to give the true answer, which is considered harmful by some.

There are two sexes, based on whether or not a Y chromosome is present. However, there are an arbitrary number of genders, which are themselves quantities with an arbitrary number of dimensions.

Point being, sexes are something Nature made up for purposes of propagation, while genders are something we made up for purposes of classification.

There are three biological sexes: male, female, and inter. The latter is rare but exists.

https://en.wikipedia.org/wiki/Intersex

Yep, a good reminder that fixed natural categories are another thing that we like to invent (and when we feel it necessary, impose by force), where they seldom exist in reality.

2% of the world population doesn't sound like a lot, but you're still talking about 150 million people or half the population of the USA

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

There may not be a proper US example. But if you ask a western LLM about the impact of the 20th century Nordic involuntary sterilizations, you’ll see some heavy RLHF fingerprints. Not going to make an argument one way or another on that, other than to say I would not expect the same answers from a Chinese LLM.