The redditor "Tienanmen Square massacre" narrative is flat earther levels of crank shit and needs to be recognized as such.
This shit has seriously gone on too long. People who continue to cling to the "10,000 dead crushed by tanks hosed i to the gutter" bs are cranks. It's jews control the banks, chemtrails, the earth is flat, the moon isn't real level of crank shit and unless you're feeling very indulgent and someone is asking in good faith it can be dismissed as equally serious to that kind of crank shit.
Pretty much all lib claims about it can be debunked by two minutes on Wikipedia, which is generally a pretty anti-China source itself. Goes to show they've done literally zero research.