Well, sort of. They're Linux's interpretation of a superset of VID/PID combinations recognized by the USB-IF. The USB-IF doesn't allow product IDs to be resold, as was (and still is) done by MCS in the $16D0 VID range, or to party on abandoned/unused IDs like C&T's at $420, as something called the "Celly SIM Card Reader" seems to be doing.

Linux is under no obligation to follow the (absurd) policies of USB-IF, so they basically have to maintain their own parallel list.