#2 John Cena wins

Some fans might see this as the ultimate doomsday scenario, especially since it simultaneously put the dream match at WrestleMania in jeopardy and allows Cena to break Flair's record in the process, but it is arguably the best move WWE could make and would add a huge level excitement to the match at WrestleMania 34.
Again, the match between Styles and Nakamura is lacking a bad guy and who better to fill that role this big match John himself. Not only will fans absolutely lose their mind at the thought of WWE's golden boy possibly coming out of WrestleMania with the title around his wasit, it also keeps his fans invested in the main event, which is a great thing for WWE.
Cody Rhodes' uncle is a WWE Hall of Famer. More details HERE.
With that being said, Cena winning the title only to drop it to Nakamura after a intense Triple Threat match at WrestleMania 34 would be the ultimate torchbearer moment for WWE and might even set up Nakamura for one of the most lengthy reigns in the history of The WWE.
In the end, Cena winning at Fastlane isn't the doomsday scenario everyone is making it out to be and could make the supposed dream match between Styles and Nakamura even better then it was before. Of course some fans aren't going to like it for the simple fact that Cena is is in it, but with his career resume, why wouldn't he be?