Microsoft today posted a support document saying that beginning on March 31, Windows 10 users will no longer be able to stream music from OneDrive through the Groove Music app. Naturally, this applies to Windows 10 PCs, phones, and Xbox One consoles. This also applies to the game Forza Horizon 3, which included the ability to play music through Groove while playing the game.
Note that this only applies to streaming music. If your music that's stored in OneDrive is synced to your PC, you'll still be able to play it. If it's not, you can still play it through the OneDrive app. But all of your data that's stored with Groove services will be deleted by the end of April, and you'll have the option to export it.
None of this news should be particularly surprising. Microsoft announced last May that beginning in December 2018, it would retire the Groove apps for iOS and Android. Naturally, chopping down the functionality of the app on Windows 10 is the next step for that.
Obviously, all of your OneDrive files will remain intact, so nothing is happening with your actual music. You just have to find a different way to play them than through streaming in the Groove Music app.