Can the Shelly Wall Display integrate with Sonos?

Yes! As of the 2.2.0 firmware update, Sonos Support is included in Shelly Wall Displays. 

To integrate your Sonos speakers with your Shelly Wall Display, ensure that the wall display and the Sonos speaker are on the same network.  Then, find Settings > Audio in the wall display, and press Link Sonos. Follow the instructions on the screen, and your Sonos speakers will be linked with your Shelly network!