In the real world, localities are routinely using Line or Twitter to send information to inhabitants. This is maybe on top of some paper fliers or announcements

In the real world, localities are routinely using Line or Twitter to send information to inhabitants. This is maybe on top of some paper fliers or announcements on loudspeakers. I don't know what this looks like in other countries, but we're talking about telling people about something, not updating your registered address.