I would be very surprised. If you've ever dealt with Microsoft professionally, you'll come to find that as long as a legit license is used on one and only one computer, they really aren't going to hassle you. If a person has harvested parts from an OEM system to piece together a new one, meaning the previous computer no longer exists, you won't have much of a hassle. Motherboards die in OEM systems and sometimes are replaced with newer, or slightly different ones, even down to a simple revision number, and you've always been able to reactivate those systems as well. There's a huge amount of gray area regarding what makes up a "computer", and even suggesting that the license is tied to the motherboard isn't really valid anymore, for the reasons I just gave.
What it all boils down to is one license, one computer, and Microsoft will be happy. Why else would you see OEM and System Builder licenses for sale, even without accompanying hardware?
In the computing industry, you can't always go by what was written....you have to go by "how it really is".