Would it not be possible to send everyone currently in the state an SMS? I personally would be okay with the government having access to this type of PSA.
I'm not sure I get your point. The notifications are sent when system detects you were in contact with a person that tested positive, so mass messages don't make that much sense.
Unless you are referring to using the sms as a marketing way to encourage people to install the application...
The latter is what I mean. Not really marketing, more like an official announcement.