Was a major vulnerability discovered?

I remember there being some talk about the EU also doing this. Is it just the EU and Australia enforcing this right now?

How would that even work? Did they think the US gov was making up the existence of other countries as some sort of conspiracy?

If you’re a propagandist then there’s value in being active in niche social media networks. It makes you a big fish in a small pond, and if the social network for some reason blows up then you’d be one of the early adopters which will give you more influence. For example Ghislaine Macwell was a moderator on Reddit, but apparently also Voat iirc, which is an obscure Reddit clone that never had a big user base