To me this doesn't seem like it's against network neutrality, after all you get a lot of bonus in return for this throttling with a much higher data cap. Furthermore for most people it's not that much of a degradation, if you are watching it on a mobile device how much better is 4K going to look as it chews through your data allowance?
Yeah, remember, NetNeutrality means you can't discriminate based on
% A bank is a place where they lend you an umbrella in fair weather and ask for it back the when it begins to rain. -- Robert Frost