However thanks to a recent server-side update (meaning that users won't need to do anything on their end), songs that you've uploaded and purchased through Play Music can now be played through the speaker as well. Users can finally play tracks from their old collections.
Subscribers will have to ask Google Home to "Play X from my library" or "Play my X" if they want to play their own content. This means that Google Home will play the special, extended version of a song that you've either bought or purchased and not the bog-standard version that the radio plays. A few weeks have passed since, and it looks like the feature is ready for primetime for every Google Play Music user. If you asked it to play you a sad song, let's say, it would still pull from on-demand playlists or put on a free radio mix, and would not dig into your purchases or uploads.
You can not specify the song location when asking Google Home to play a track by genre or mood. New Release Radio takes what you have listened into account through machine learning when creating the playlist, giving it a more personalized feel. In accordance to reports from Google's Product forums, the newly extended Play Music component will be featured in all areas where Google Home is available.