[g-b-r]

> some phones reportedly spoke the announcement rather than just beep loudly.

Reportedly, some phones have a setting to toggle TTS for emergency alerts...

[geoah]

^ this. Most likely just an accessibility setting.

UK's emergency alert system [1] is based on SMS-CB [2] so it's just test based.

1. https://en.wikipedia.org/wiki/UK_Emergency_Alert_System

2. https://en.wikipedia.org/wiki/Cell_Broadcast