The problem with that logic though is that very little qualifies as content. A new weapon? That is just as "extra" as higher difficulties. A new model? "Extra". A new ability? "Extra". A new zone? "Extra". That is the problem when you subjectively decide what is and is not content. Features or Content. It is the same thing and it is only being split to argue a technicality.
And that technicality only exists so they can subjectively label things as bad or good depending on their own personal tastes. Hence why they defeat their own argument in their very post by the contradiction of saying a new phase (new abilities) is arguably content but abilities are features.