This new feature drove me crazy on my two machines. I wonder how many other users have problems with it. Point 1 is: this option should NOT be enabled by default! Risk of data loss, see below. Point 2: it needs more configuration, see below too.
Machine 1, desktop: has a 1 TB drive in a mobile case, although connected to the internal SATA ports. It forced me to disable this feature as it popped up every time I sent the machine into sleep, and I use sleep a lot.
Machine 2, notebook. As I was used to do it I simply closed the lid. The machine then enters sleep state. On next morning Windows told me that the system had been saved into hibernation because power (battery) ran off. On the second day I finally noticed the unit was still up and running when opening the lid again. USR had prevented sleep mode because the internal webcam and keyboard/touchpad are seen as removable USB devices, so USR waited for confirmation (which I didn't notice - lid closed already). Again I had to switch off this feature as it makes zero sense this way (and I am glad my hybrid sleep/hibernation state works so well).
Obviously the user should be able to define which devices are used for the 'Forgotten devices notification', or the feature is useless. This blacklist can easily be provided by adding the feature of notification to the device property dialog, section device behavior, for every single device. Set it to default as 'on', so new, formerly unkown devices are included, but problematic ones can be disabled. This way I might get tempted to turn the global switch back on...