I know some Mastodon users were really unhappy at the existence of this back when it was first announced. But as far as I’m concerned it’s entirely a good thing. Even less centralisation, and it’s not like any content shared on Mastodon could be taken to be private at all anyway.
Ah damn. I just came across the first time I wanted to actually use this. It requires opt-in from both ends‽ No wonder people aren’t upset, the damn thing is nearly useless.