Or, why would a potential terrorist put a bomb on a plane with an active Bluetooth beacon advertising a bomb, if they don't want it found pre-explosion?
The whole thing is stupendously idiotic. Even if someone built a bomb to put on a plane, they wouldn't use Bluetooth. They'd use WiFi and have it automatically connect to the in-flight WiFi SSID once it's in the air, and then use the pathetic security that allows you to download an app from the app stores to breach the router to get to the Internet.
Nobody intent on doing actual damage would have left a Bluetooth device beaconing "Bomb" because that would be pathetically stupid. Like, even more stupid than the shoe bomb guy.