From the email:

Apple Music will be launching on June 30th. If you upgrade to iOS 8.4, iTunes 12.2, or the latest update of Beats Music, you will be prompted to join Apple Music and get 3 free months when you start your membership.

Apple Music will not be available on Sonos when it launches. However, we're already working together to make Apple Music available on Sonos before the end of the year.

If you decide to start the trial, your original Beats Music account will be cancelled and will no longer work on Sonos.