this is the first time I’ve heard them being blamed for the Tiananmen Square massacre.

Well you’re not going to hear it in corporate journalism, in US- & capitalist-funded NGOs, or in corporate social media. The books on it aren’t going to show up on the NYT bestseller list or at airport bookstores or Barnes & Noble. They’re written by scholars/historians/researchers who know they probably won’t break even for the effort, if they manage to get published at all. Nor will you hear it from “neutral point of view” Wikipedia. I already covered this stuff upthread. You really have to go out of your way, which few have the time or energy for, and anyway almost no one would have a reason to question what they take to be bipartisan “common knowledge” in the first place.