According to my aunt, whose parents fled the Cultural Revolution when she was a teenager:

It's like if Chinese people kept trying to give you shit about the Kent State massacre and not Vietnam itself.

From my conversations with mainland Chinese, they often tout the line that the US was somehow involved, so it was partly an excusable defense of the homeland against dangerously co-opted students. That said, most acknowledge that it was pretty bad. But these are also well-educated Chinese working abroad, so I assume the majority of Chinese don’t know much.

One story I heard retold by an English teacher working in Nanjing that I used to know was about the experience of one of the people involved in the protests…or at least they were an academic in Beijing at the time of the massacre. They were really depressed 20 years later and felt that nobody around them, particularly their students, knew anything.

The people I have spoken to in China understand something happened, and most of them know that it was the suppression of a student protest movement. From there the knowledge diverges as to what kind of protest movement and how violent was the suppression and whether it was justified. My family will kind of halfheartedly repeat some version of the party line but acknowledge it was a fucked up situation, and they also understand that the censorship surrounding it is awkward and unnecessary.

Generally the Chinese I have spoken to are mostly aware of and opposed to the CCP's censorship, but they also don't really like to talk about it for obvious reasons.

閉嘴書呆子