In the U.S. at least, most jurisdictions will require the music to be shut off in an emergency -- namely, if the fire alarm goes off. Audio sources commonly are required to have a relay/GPIO input that triggers the shutoff, a network command is not good enough (network switches typically not being life safety rated).
In this hotel scenario, you have one audio source that can be located in a location that can be conveniently tied into the fire alarm relay panel. Stop the audio there and you've stopped it everywhere.
