1) they are allowing customers to opt-out (maybe they will concede this could be improved, but it doesn't change their fundamental desire to circumvent net neutrality); 2) content discrimination has positive benefits for consumers (i.e. allows higher consumption of content)

T-Mobile may be willing to bet that the FCC and consumer groups will be hard-pressed to claim that sending HDTV vs. EDTV falls under a discriminatory context given the consumer benefits and (seeming) fulfillment of video service.