I think you'd be surprised to learn most Chinese know about the Tiananmen Square protests. It's within living memory and the government has made statements about it which can be found in archives etc.
Most Chinese don't want to talk about it because it's considered a source of national shame. (Westerners often interpret that as them being afraid to talk, but that's not actually true.) They also believe the events are used for foreign propaganda which is not entirely untrue.
So that’s why the CCP blocked all versions of Wikipedia in conjunction with the 30 year anniversary? Because they didn’t want to bother people with shame?
In Germany people have a completely different perspective on the Holocaust. It was horrible and a source of great national shame, but still, never forget. Blocking Wikipedia on Holocaust remembrance day would not happen in Germany.
Most Chinese don't want to talk about it because it's considered a source of national shame. (Westerners often interpret that as them being afraid to talk, but that's not actually true.) They also believe the events are used for foreign propaganda which is not entirely untrue.