The only way HBO MAX can make it is by cheating - and Stankey knows it.
"Zero-rating has been broadly criticized for years by net neutrality advocates, as giving any service preferential treatment tilts the competitive scales. For example, AT&T customers watching a third-party video streaming service from Netflix, Disney, Comcast or Apple, among many other contenders, will have that usage count against their data caps, encouraging them to instead watch the service that AT&T owns."
https://www.fool.com/investing/2020/06/03/att-will-zero-rate-hbo-max-undermining-competition.aspx