How to stop MPMusicPlayerController from playing when application terminate by user?
Unfortunately your only option based on your requirements is to play the audio using your own app, AVAudioPlayer for example and set the audio background mode requirement.
As there is no way of receiving a notification when your app is terminated by the OS or by the user, you have no way around it, you will not be able to stop the system or application player from your process.
Registering for NSUncaughtExceptionHandler
wont catch SIGKILL or SIGSTOP either so you cannot rely on the system music player.
This shouldnt be a problem though as its easy to setup audio playback in your app. If you are using the system player so that the user can play their own music, you should use a picker and access their music library so that they can choose the music.