By that time they'll just add an extra field to the protocol and assign a special "see other field" VID/PID pair. For a lot of products the VID/PID combo isn't

By that time they'll just add an extra field to the protocol and assign a special "see other field" VID/PID pair. For a lot of products the VID/PID combo isn't that important on a protocol level, and there's technically no reason why two completely unrelated products couldn't be using the same pair. In practice you're mainly going to use them for software to target a specific device, for example the Linux HID driver uses it to work around hardware/firmware bugs. But HID devices are self-describing, and that's the main mechanism used by the driver to figure out what has been attached and how to behave. If modern OSes can do the same to distinguish hardware with the extra field, sharing the same value for backwards compatibility with legacy machines really isn't going to be a big deal. It's not like MAC or IPv4 addresses where a clash will essentially kill all communication.