For a little while near the end of 2016, it looked like things were shaping up to finally give us the John Cena v. The Undertaker WrestleMania match that so many people had been looking forward to for years. And that actually was the plan at one point. So, why did things change?
Well, according to CageSide Seats, the WWE felt that Cena v. Undertaker wouldn't be as big a deal as Cena proposing to Nikki Bella in the ring - and based on the all of the coverage that the proposal has gotten in, and outside, the WWE Universe, they were probably right.
Also, Vince McMahon wanted The Undertaker to put Roman Reigns over before he retired - although, that part of the plan, it could be argued, was much less successful.