The latest version of YouTube’s Android TV app now supports 8K video.
Viewers need an 8K Android TV running Android 10 or later. The TV needs to support the AV1 codec support (with 8K decoding) and the YouTube app must be updated to version 2.12.08 or later.
Another new feature in the updated app is Cast Connect, which “allows your Android TV app to receive messages and broadcast media status as if it were a Chromecast.”
According to Android Police, the update originally mentioned AV1 HDR playback support, but this was later removed and replaced with Cast Connect support.