Even if it's true, it doesn't matter. When you're talking about an installed base, from a business, real-world perspective, you're talking about units that are going to consume through official channels and take part in the economic infrastructure. A piracy box is largely irrelevant, except in a negative way.
I'm pretty sure Microsoft isn't going to release a statement bragging that there are actually millions more out there with Xboxs playing unlicensed games.