YOU WILL SEE THIS NEW FEATURE IN ANDROID 13 SOON..!

Image Source - Google News

Android 13’s Audio Output Switcher will soon show Cast Devices..!

Currently, the only playback devices that could be listed in the output switcher included the current device and any paired Bluetooth devices. But with the Google Cast SDK update and the new Android 13 'Stream Expansion' feature, you will be able to expand the audio to multiple cast devices. 

Originally, the feature was introduced back in Android 11, but was then disabled for some reason. And now, it looks like Google will bring it to back with the Android 13 remote playback system API.

Besides that, support from the app side is must, so if you're an app developer, we highly recommend checking out Mishaal Rahman's article on Esper:

Esper Blog