It’s discussed in the article. We can’t really be sure if they do, but they already store the measurements of your face along with other bits of metadata. They could reconstruct your face with it even without the photo. It’s a deceptive claim, because even if they throw away the camera video they still have your face for all intents and purposes.
That’s a strawman, who said otherwise? Showing ID is one thing, storing your ID and tracking your trips is another.