My guess is, at first especially, the facial recognition will have pretty low sensitivity. Which is really all that is necessary, as a way to prevent significant ticket fraud.
This ticket is linked to a 16-year-old white male with brown hair -- Merely confirming that the ticker user is a white teenage male with brown hair, might be good enough to prevent any significant fraud.
My understanding -- It's not facial recognition from scratch to enter. It's simply making sure the face matches the swiped ticket/magic band. Replacing the fingerprint scan.