Just wanted to give a little positivity - music library is back to the Android app!
Searching the music library is back!
PLAYING music from the library without it crashing is back!
What's more it seems the menu and features are thought out and aren't simply bare bones.
What is not back:
Album art on music library tracks
Sonos playlist creation and editing. But this is listed as a future update and I am a little more positive about the chances it'll be returning.