It's from manual bans, not defederation. Both Butts@ani.social (the parent comment in this chain) and CJOtheReal@lemmy.sdf.org (commenter providing a critical summary of why people are upset) are banned at LW.

At the time of writing this comment, by looking at the LW modlog you can see Butts was banned 3 hours ago because "fuck those guys" and 17 hours ago CJOTheReal was banned because "LW admins are assholes."

I am guessing those ban reasons are quotes from the banned users themselves, not the actual reason why an admin personally banned them, though that hardly makes it justifiable - in fact it does the opposite by proving that LW admins actually are power tripping and banning for petty reasons.