It looks like I was wrong to assume that it was tied to the .edu domain name -- I thought notion was using that as a way to avoid pouring resources into verifying eligibility.
My wider point is that it's disingenuous to have a bold heading [0] "Free for individual students and educators", and then in the FAQ lower on the page state:
"You're not eligible if...you're a k-12 student or k-12 educator"[0]