Why should an advanced civilization necessarily create the artifact mentioned in the article. The conclusion because we don't see this artifact, so type III societies don't exists seems too strong. Maybe they don't create giant veils around galaxies and instead have virtualized themselves, or can simply convert matter to energy at will. What use would there be in wrapping a giant ball of dust around a galaxy when you can convert matter directly to some other energy/form? Probably I think "they" are formless and more information based than physical. We aren't even sure if this reality is real or a simulation anyway, so why limit our thinking to advanced civilizations in the world as we know it?