After restoring the .generic kernel (see Bug #232019), the behavior has changed. The System..Hardware Drivers Manager now shows the restricted driver, and selecting it gives a warning explaining what it is. After this I am prompted to reboot. After reboot, the nv driver is still in operation. Even though the restricted driver is still shown as "In use" on the System..Hardware Drivers Manager.
After restoring the .generic kernel (see Bug #232019), the behavior has changed. The System..Hardware Drivers Manager now shows the restricted driver, and selecting it gives a warning explaining what it is. After this I am prompted to reboot. After reboot, the nv driver is still in operation. Even though the restricted driver is still shown as "In use" on the System..Hardware Drivers Manager.