This only matches with digitizer devices for now, and its purpose is mainly to make testing possible with the virtual device on Wine, but could be ultimately useful for hidraw pointing devices, assuming we would support that in winebus / wineusb.
Later, it could also be extended to support mouse devices, but for now we use a different path with user drivers sending the hardware messages instead. Using a NT device for that has a lot of performance implications that will need to be resolved first, and it's unlikely the best way to do that. On the backend side, accessing the raw mouse devices usually requires privileges anyway.