It's hard to know who is at fault but it is obvious that an update in the OS brought the problem to a head. It could simply be there was a problem with the USB controller in the optical drives that was "allowed" but technically not in spec and Apple in the name of security patched the OS to close that hole. Years ago Microsoft updated Windows 10 USB drivers and it bricked a lot of devices using FTDI USB chips because they were giving out the wrong ID during handshakes and Windows thought they were counterfeit. This could be something similar. Just because it used to work doesn't mean it was working correctly. It just means that it was tolerated.
Since this is the first version of MacOS to natively support USB security keys I would think Apple buttoning up the holes in their USB drivers to make them secure would be the first places I would look.