Nope, not true. The lid is thin and you need space for sensors and camera components that you can just place it behind the camera in thicker devices like iPhones and iPads. Face ID would require more Z-depth, at least at the current state of technology, so it was likely never an option when they designed it. Eventually it may be possible to put it there, but that's not the reason why the notch is as big - you simply need space for the components. And since the lid is so thin, you can't put them behind the camera, you have to put them to the side.
Do you know a single laptop that has a camera of that quality, in the top part of the lid - and such thin bezels? Tell me.