When I was on the phone with them the other day, that's the first thing I asked. This is a pretty significant bug if your Trackpad is disabled and you need it enabled.
Unfortunately, no info from the Answer Tech regarding the Registry settings.
If your Trackpad is disabled with the update installed you can re-enable it by going into Device Manager, Human Interface Devices, Right Click on Touch Cover Trackpad settings and uninstall it. Restart you device, run Windows Update, and let it re-install the Touch Cover Drivers which will enable the Trackpad by default..