The XROrigin throws a warning if the Camera does not have the TrackedPoseDriver component. I have the TrackedPoseDriver on a different object that copies its transform to the camera (using Game Creators Camera Shot System). This warning semi-imposes a scene-structure without any need for it - my project has a zero-warning policy. IMHO it should be removed - users should already know that something needs to control the camera as usual and can also observe this in the ARFoundation documentation and samples.
It is improper use to use a XROrigin and Camera without a TrackedPoseDriver on it. That’s how the system was designed. You may want to look into mentioning this use-case to the developer of Game Creators Camera Shot System.