How is that keeping Microsoft from accessing your GPS, sensor data, wifi, camera/microphone etc? Sure, they can't get at SMS or your other apps and your work won't have access to your entire device but it means MS can still access your location (using GPS and nearby bluetooth/wifi), record audio/video, read/control sensors (accelerometer, proximity, gravity, temperature, pressure, magnetic field etc), have full network access, etc and can record and collect that data whenever they feel like it for the most part.