Add Google if you like because the key is all about creating suggestive selling. And wrt the Apple Music app, it's a joke on Android. I tried it and I can't even stream music that I purchased.You can uninstall Apple Music, same as IE or edge. (actually I'm not sure you can uninstall edge)
Android includes google music and youtube. How is that different? Should they include apple music in their OS?
Should an iPhone really include a dozen different music services pre-installed?
Should all smart tv's include Sonys playstation tv service?
Should direct tv boxes also include dish network?
Not every item should include everything that every competitor offers.