I will preface this by saying I don't think any of the guys will break 2, and I don't think anyone at Nike does either. Great marketing for a shoe, but sub 2? I don't think so.
That being said, if Nike is trying to maximize every last percentage, shouldn't the athletes run shirtless? It's not a huge difference, but with the extra weight of a singlet (granted not much) and the extra air resistance, wouldn't the athletes (Kipchoge) have a better shot at two hours without a shirt?