I wouldn't pay a terrible amount of attention to this article's source. Not only are they unnamed, but they don't seem to really know what they're talking about. I wouldn't call Amuro Namie "reggae," and even "hiphop" is a stretch. This person, probably not really with the times, doesn't have a strong grasp on what the different genres of music are. He/she probably just means stuff along the lines of "STEP you" and "INSPIRE". They seem to be more common in today's Ayu - after a lot of rock, she's edging back to her roots, it seems: an evolved, rock-infused form of what "A Song for XX" was originally aiming for.