I have never heard of it, but, I see the logic in it. However could be a nightmare of physically getting in between the rows to pick the corn. If you do that, post your results at the end of the summer or in the fall.
FYI, corn is a heavy feeder and likes fertilizer (IE...10-10-10). If you have pumpkins growing too early in your rows, then you will not be able to get your fertilizer in the ground without hurting the pumpkin vines/ runners...