Hacker News Reader

Yes, they explained that the UK's regulations are less aggressive so it's possible to comply with them

Their wording had me imagining technological schemes that blind BlueSky from knowing but reading again I think what's going on is:

Mississippi: They track "underage" and "adult" UK: They track "unknown [treated as underage]" and "adult"

The UK only requires verification for specific content. Not the entire site. Also, the identification and tracking requirements are very different.

I'd prefer all businesses impacted by the draconian Brit legislation block the Brits geo completely.

They could based on group but you can get around that. Maybe they are concerned that a user using a VPN from Mississippi would cause them to break the law.