It requires you to click a checkmark box for "I agree to the restrictions" to add it to your cart. I suppose that's what they consider to be restricting your usage to their approved use cases, not copyright.
I suspect adding anything about restrictions was a last-minute job for Seeed, and it's probably not something given too much effort on their part. Realistically, an $85 devboard isn't going to end up being built into production items. And they're probably going to be a low enough quantity item for Seeed that they can manually look into any instances where someone has ordered more than 3 or 4 and just stop sending any more to them if it really rises up to being enough of a problem for Microsoft to complain.