Apple mentioned HomeOS in a job listing.
You'll get to work with system engineers across Apple, learning the inner-workings of iOS, watchOS, tvOS and homeOS, and optimizing your code for performance in ways only Apple can. Come join our team and make a real difference for music lovers worldwide.
The Apple Music Frameworks team owns the technology stack that enables the system-integrated Apple Music experience on all of our mobile platforms: iOS, watchOS, and homeOS.
This is definitely something to keep an eye on. Apple's privacy emphasis certainly makes the thought of them getting further into home automation really interesting. It's likely that all their stuff will be pretty darn well done, but really expensive (though AirTags were quite reasonably priced, so who knows?).