This is some LLM-level of analysis right there (Lemmygrad.ml and hexbear.net are blocked from many instances, and people often lump lemmy.ml together into a triad, hence lemmy.ml must be automatically blocked as well!).

I’m the author of the comment you quoted, and even though you didn’t reply to me, I’d like to say that I assumed this because of this.

ignoring how e.g. lemmy.ml kicks people out of communities

Who is ignoring it? I think it was widely discussed on the Fediverse.