"We don’t build a profile based on your email content or web browsing habits to sell to advertisers. We don’t “monetize” the information you store on your iPhone or in iCloud. And we don’t read your email or your messages to get information to market to you."

I don't think this precludes Apple from ever building better predictive services. Tim Cook is specifically saying that Apple does not sell or give away your data to third-parties for advertising purposes. He is NOT saying that Apple would never ask permission to read your e-mail if it meant that they could offer a compelling Apple-created product and user experience as a result.

For example, with Apple Pay, Apple is technically using and storing my private information (my credit card data) to offer me a compelling service. They are not going to then figure out which credit card I own and/or how much I spend, and sell that info to banks so that they can target me with specific credit offers.