In tvOS 12 and 13 there was an option in settings to output audio to an AirPlay device. This option is now gone and I used it exclusively for my audio needs (there is no audio device in my HDMI chain with my particular setup and I cannot add one - I have my reason).
Was this an oversight? I hope this option returns otherwise the AppleTV lost its one reason in my setup (avoiding an HDMI audio extractor by streaming to AirServer on my PC).