I have absolutely had anti-tankie comments deleted on Lemmy.ml. I literally just said something like “Hexbear is a bunch of tankies” and it got deleted.
That being said, I wouldn’t support defederation just because they have some annoying mods.
Edit: a couple other points. OP has a 3 day old account that isn’t from ml but is named in reference to Lenin. They posted anti-US imperialism stuff to a community dedicated to complaining about ml and tankies. Thats just off topic and spamming a community. I suspect OP might originally be from ml