Audio playing in background even after I kill the app?

This may not sound like a developer question. But... bear with me, please:

There are two streaming audio providers (Spotify and LiveXLive) whose audio plays after their respective apps have been sent to the background. This is behavior I expect and want to see from streaming audio apps. But they tend to be... shall I say... overly aggressive about playing audio. They stop if I disconnect from my bluetooth device, but when I reconnect, even if I've killed the apps (to the extent that you CAN kill apps on iOS) - by double-tapping the Home button on my iPhone 8 Plus, navigating to the app I want to kill and sliding up - those apps starts playing music in the background anyhow.

I've had quite an interesting discussion with LiveXLive support. They insist that, according to their developers, this is how Apple wants apps that play audio to behave. I argued that if that's the case, why do two other very popular apps (iHeartRadio and Audacy) never do that?

And -- here's why I'm posting this question in the developer forum -- this assertion from LiveXLive DIRECTLY contradicts my experience as someone who's WRITTEN iOS apps that stream audio.

I am 100% convinced that LiveXLive's reply is a huge, smelly, steaming pile of crap, but I've been wrong about other things, and maybe I'm wrong about this. What's the official word?

Thanks in advance!

Audio playing in background even after I kill the app?
 
 
Q