Whenever a site is to be launched as a public beta, or when a site at a beta stage becomes a full fledged site, will a notification or announcement be given to SE users or area 51 users?
Early in a site's launch (reaching private and public beta), email announcements are sent to those following the proposal. But once a site has been established. the meta site serves as the forum where graduation readiness and procedures are discussed. No email announcements are sent.