They didn’t “join” anything. They just made an app that allows Meta-owned users to talk to us here in the Fediverse, but we can’t talk back.

Jumping into a conversation that people were already having, but you’re the only one that gets to talk, is hardly “joining” it.

Not to mention, their API requires creating an Instagram account. The Fediverse doesnt require accounts just to view public data.

All these years and Meta still hasn’t learned a thing about an open and free internet. But you can put lipstick on a pig, I guess.