Ok first I'm gonna point out that I don't wanna re-litigate any of this and I'm not interested in conversation about the content, but rather how the conversations normally go. I'm honestly not an expert on this stuff and it's really tiring constantly talking about them. The main things that end up being fierce discussions right now are issues with China (namely Xinjiang and the 1989 Tienanmen square incident), and sometimes issues with the USSR (namely the 1930s Ukranian famines).

it seems like that no matter how much discussion is had on this stuff, nothing budges, no one comes away with different ideas and none of it matters. It always devolves down into shit-flinging, because the conversations themselves are proxies for current unresolved political contests. I don't think the historical content of the stuff even matters anymore. Furthermore even scholars on these subjects are divided. There isn't a consensus among historians on if the Soviet Union is responsible for genocide, there are nuanced stances on Tienanmen square, and there's a vast gulf of stances on how Xinjiang is talked about. And that's because it's all still part of the same proxy for political competition. These historical incidents are not yet resolved as unanimous because there is still an ongoing worldwide conflict between powers that could broadly be described as capitalist/western/wealthy and another set broadly described as socialist/unaffiliated/poor.

so even in civil spheres like international diplomacy and academics, talking about genocide or the nature of historical events can be highly politicized. There's also a lot to be said about admitting certain deaths occurred without ascribing certain political motivations to them. That seems to be a massive point of contention specifically. For instance, I might say that the events of Tienanmen square did occur, but the way they're talked about is misinformed or that the conflict is presented in an incorrect framework, which is the standard kind of Marxist view of the event. Liberal frameworks might say it was a conflict between value systems, between freedom and tyranny, whereas a Marxist might say something more like it was an event caused by social dissatisfaction with the Chinese market reforms started in the 70s, and this dissatisfaction came from both a working class socialist perspective and a more wealthy liberal perspective.

To some people this is unthinkable, to present it in a different framework is to deny accepted events entirely, and I don't think that's true. Scholars are constantly redrawing the frameworks for why events occurred, and all history is going to be seen differently by people of different class perspectives.