I think that's valid, but from what I've seen, it mostly relates to Western propaganda against China.
I don't trust the US or Chinese governments, really, but I can at least admit from a Western perspective, a lot of stuff promoted about China is propaganda, and I don't disagree with the admins that it can be perceived as "racist." I agree with the admins on that and it seems that is mostly where the accusations lie, with them supporting China. I think that's fair and China is just as full of actual real humans (actually more) than the US and other Western nations. Painting all US citizens or all Chinese citizens with a broad brush isn't acceptable. Valid critiques of their government should be, but a lot of Western critiques can often (and should) be dismissed as not valid, highly propagandist, or even racist.
Example: US people complaining about China's "Social Credit Score" while having no issues with the US "Economic Credit Score" even though they achieve similar goals.
Anyway, that's what I've seen. People post something that's anti-China from a Western perspective and admins remove it.
Also, "if you don't agree you can gtfo" is kind of the entire point of federation. You can always choose another instance that these guys don't run. I think that's an entirely valid attitude, and it's one that allows the Fediverse to grow instead of stagnate on one server.