#4 John Cena wins

This one seems strange to say, but yes. John Cena should defeat this young up-and-coming star at one of their biggest PPVs.
You might be asking yourself "Why? Why at this advanced stage of his career should Cena be racking up wins over guys who could use them much better than he could?" Well, it's basically because Cena isn't going anywhere anytime soon. And he also just lost clean to Shinsuke Nakamura on SmackDown. Losing clean yet again would begin to deteriorate his aura.
Is this man the funniest man in wrestling?
Cena is known as one of the most unstoppable forces in WWE. That's exactly why clean wins against him, like Nakamura's, feel like such a big deal. But if he accumulates his second clean loss in roughly a 3-week span, it won't feel like as big of a deal because the real story will be that Cena has lost a step.
Plus, Corbin is Mr Money in the Bank. Whether you agree with it or not, Mr MITB is typically not booked well leading up to his cash-in. But he doesn't really need to be as he'll likely be on top of the world in the near future. In this particular match, it makes more sense for Big Match John to come out on top than it does for the rising star Corbin.