And for the wide majority of customers, like 90%+ of customers, it won't.
So everyone here who cares, being more informed and sensitive than the 90%+ of said customers, loses (though it can be argued even that a bunch of us here wouldn't lose anyway because we don't come near to reaching said cap).
AT&T is saying this will only affect 2% of there customers. So 98% of customers "shouldn't" have a any actual issues as a result of this change... in theory.