Just had my first PC recieve CU and afterwards it wouldn't boot into Windows because it couldn't detect my SSD. Didn't feel like going through the rigaromole of spending possibly hours or days trying to diagnose so restored previous version of Windows.
Makes me leary as to what we'll encounter when the other 6 have the same update applied (assuming eligable), they too have SSDs.
Essentially i believe it to be a driver issue and can only assume yours may be same. Personally, not willing to deal with it right now to find out.