Firstly, this is not 'advertised' - this is not a material average apple consumer reads.
Secondly, it does not actually say anything about the OS phoning home and preventing the user from launching an app. The appleinside talks vaguelt of 'Notarisation', something thay can be inplemented in a variety of ways, like signing application with a certificate
Here is a Forbes article (do “normal” people read Forbes?) that says to run apps in Catalina one will need permission from Apple. It even anticipated this problem with the server. Sure, it doesn’t mention sockets but remember this is for normal people and I think people are smart enough to assume that Apple is probably not giving permission to launch an App by carrier pigeon.
There are 100s of articles like this. Gatekeeper was a keynote feature.
Secondly, it does not actually say anything about the OS phoning home and preventing the user from launching an app. The appleinside talks vaguelt of 'Notarisation', something thay can be inplemented in a variety of ways, like signing application with a certificate