If Nintendo and all other corporations really are blocking console IDs to their own network servers, then it'll cause a huge public outcry. Not only by individuals, but also retailers will also complain about it as well, which will lead to cuts in the amount of sales as well as retailers refusing to stock the consoles or games. If they really are blocking access to the internet, they could be just blocking their IP address from online multiplayer, as well as their account. If the unique console ID really was getting blocked, they could easily just buy another console and modify it again. If this really is happening, then why exactly are the individuals and retailers not complaining about it?
Ah I see, I've just checked Mario Kart 7 and noticed it only had the header ID in which was different between the one I downloaded ages ago and the one that I dumped just now.