This is yet another in a long line of glucose-measurement devices designed to sell to unsophisticated research grantmaking agencies, rather than to diabetics. Making a device that "measures" blood sugar in a watch form factor is easy, and many research groups have done so. Making one that's accurate enough to compete with the CGMs that are already on the market is a different matter entirely.
If you're type 1 diabetic, accuracy is paramount, especially in a closed loop insulin pump setup. Even with access to the bloodstream, existing CGMs leave plenty of room for improvement that would directly improve quality of life a lot more than the annoyance of applying the sensor under the skin.
