The missing child should absolutely warrant an alert, it's super important that they are brought to safety and anything helps. Anxieties coming from this alert spawn from threat of Russian nukes after they began their invasion in Ukraine. Canada has a strong relationship with UKR
Canada misuses the alert system by marking every alert as a Presidential Alert which is why it triggers an air raid siren and the settings menu doesn't work. They don't want the air raid siren noise but rather they set an incorrect alert level to stop people having an opt-out.
It's not how the system was designed to be used and isn't how it works in the US or elsewhere in the world.
They're unnecessarily waking people up and scaring them, which is genuinely harmful especially to people with certain health conditions and disabilities. It's not smart.