I think those alerts are managed by government entities.My complaint with the current alerts is they should be a bit more contextual. My phone knows I am asleep at 3am. A loud amber alert at 3am, unless it is for literally next door, is not ideal. Alerts should be better targeted. Often they are looking for a car on a highway, so the most effort should be made to let someone driving in the area know of the alert.
Apple should only allow those alert to sound on the phone itself. The problem is that if you happen have your phone in your ear you will get a nasty blast too.