Would Google consider it an unnatural link? Probably, if they detected it, and especially if it's not really relevant to your site. Which it sounds like this would not be, based on what you've said.
Would Google succeed in detecting it? That's a much harder question. The algo can't guess right every time, so you have to try to guess what factors it's looking at. Which is why I brought up relevancy. I'm surprised Google hasn't already devalued or penalized these links, since it sounds like there's a relevancy issue. But it sounds like their "trust" in an edu domain may be trumping their concern about relevancy. So you may be perfectly safe to do what your competitors are doing, but unfortunately there's only one way to find out.