Yes and no. Shotguns have their minimum specs, just like the rifles and pistols do. This Shockwave pattern, though (and the Remington TAC-14), technically aren't "shotguns." They are only "Firearms" by definition. It's the way the law is written, directly, and what those two companies have done with the direct wording of those laws.
Sure resembles an SBS, though, right? Especially like this - here's how mine is sitting, right now, with a pistol brace: