I mean, sure, you could say that if you want to split hairs, but Madden's game is nominally football. So yes they are teaching football through a video game. Teaching a person how to use a Levels passing concept or the strengths and weaknesses of a Cover 2 coverage applies in Madden and real life.
We all know Madden has shortcomings in the way some things play out on the field, but that doesn't mean that what it teaches isn't representative of the sport whatsoever.