No, he's referring to longer top tubes on the same size bike, from brand to brand.
Simply put, most of a bike's geometry characteristics are tied together in one way or another. Some manufacturers have geometry that they stick to, that may call for a certain length top tube. For example, Gary Fishers tend to run long in the top tube and that works into their overall geometry. This works well for some people and less so for others.
A bike with a shorter top tube will typically handle better at speed and in the air. Longer top tubes are traditionally reserved for racing and xc bikes oriented for more climbing.