Stream to multiple Apple TV's

Hi there. I was wondering if it's possible to stream audio via AirPlay 2 to multiple Apple TV's. I do have the old Apple TV with optical-audio connected to a mixer that is connected to studio monitor speakers that are in my living room. Now I'm thinking about also getting the new Apple TV 4K for my television in combination with a Sonos Soundbar. Would it theoretically be possible to stream music to the Apple TV 4K (and therefore hopefully the soundbar) and to the old Apple TV at the same time?