FaceID was just one example they gave (which is probably faster and more energy efficient now).
Image recognition, OCR, AR and more are applications of the NPU that didn’t exist at all on older iPhones because they have would be too intensive for the chips and batteries.
That's false. Face ID is in fact a complex form of image recognition, so image recognition was definitely possible on older NPUs. OCR is the simplest form of image recognition (OCR was literally the first application of LeCun's CNN), so this was definitely possible as well. "AR" is an extremely vague term. If you refer to Snapchat style video overlays, those have been possible for a long time as well.
Image recognition, OCR, AR and more are applications of the NPU that didn’t exist at all on older iPhones because they have would be too intensive for the chips and batteries.