It is my personal opinion that the Old School/New School divide is one more false dichotomy we gamers have inflicted upon ourselves.
And, in general, if your reader is so new to the concept that they ought to have a definition of "RPG", then the differences between Old and New are going to be lost on them. It is only relevant to people who are already trying to pick one style over the other, or who already has a grasp on the basics, and interested in deeper design philosophy.
Thus, I'd say either eliminate that section altogether, or keep it more conceptually separated from the, "What is an RPG?" section.