@Mycroft icosa doesn't block anything and federating with them comes with a lot of potential exposure to people we don't want to be able to see folks from our instance as much as possible to limit abuse
having private post federation means that we can sidestep that problem bc people can use private posts to avoid that now
but it comes with its own set of problems, mainly that it effectively asks people to enforce themselves in *more* of a bubble to allow us to federate with icosa