On the main instance they’ve banned a few accounts for comments about human rights abuses in authoritarian-left governments. But it’s true, that’s instance specific. I know that on Mastodon the original instance, mastodon.social, has kind of set the tone for the other instances, so there could be an effect of that sort. Other than that? I’ll just be honest and tell you that I’m not sure. It’s hard to predict these kinds of things. But I agree with feditips that it could be a cause for concern.
You can look at the modlog and see that lemmy.ml has also banned people for criticism of authoritarian governments. The reddit post I linked to in regards to Tiananmen Square was posted by one of the moderators of lemmy.ml.