Makes more sense than ever to get rid of requirement to have iTunes open. Was just discussing this with someone having problems with their Apple TV not seeing their libraries from their Mac. I told them it was working fine for me as long as I had iTunes open and just realized it was required for iTunes to be open to see them AFAICT. Anyways, I'm running latest public version of macOS not the beta that apparently removed iTunes which I didn't know about but sounds like a bad idea!
p.s. Also, restoration of an Apple TV requires the use of iTunes so unless they come up with new way to restore it which is already a problem with the Apple TV 4k without usb port all other Apple TV owners will also be out of luck in future!
I'm having the same kind of issue
I updated both my mac and apple tv to the latest beta and now home sharing wont work.
I have logged in and out, restarted everything etc but nothing shows up in my library.
I also cant even connect my iphone (on the latest beta) to Airplay
Its driving me insane