Yeah it's definitely a different way of going about things in general. It's an interesting situation. I'd call it a feature of the platform because, at the end of it, the instance owns the data and has the "canonical" version of it, in the sense that it's the origin.

If beehaw had the option of staying federated while having an instance-wide whitelist/blacklist of communities and users, then they would've gone that route, I bet. They mentioned wanting more granular moderation tools.

No one Lemmy instance can forcibly administrate another, so anything that's added on top of the act of de-federating is actually less restrictive.