I have made a simple automation with Apple Home on iPhone to start music when I got home. I have an Apple TV to manage Apple Home. It has worked at first attempt and also I made an interesting discover.
Basically the music is played from the Apple TV and airplayed to my Beam and One, but the Apple TV stays off (at least: the led light is off). also the TV has not been turned on.
So it seems that the Apple TV is capable of airplaying music without turning on the TV, but only with an automation. would be nice to use this features also from Apple Music, this would be a very good alternative to Sonos App, because basically your smartphone is not streaming anything, just link with the Sonos app