Sources report that there was a massive last-minute re-write of RAW on Monday afternoon. Early in the afternoon, they were going with Triple H vs. The Undertaker at SummerSlam and Taker vs. John Cena at WrestleMania 28. A few hours later they made The Rock vs. Cena announcement, which is a significant change within just a few hours.
There’s a feeling that the long-term plan has always been to build WrestleMania 28 around The Rock, even if he wouldn’t agree to wrestle. This could have played a factor in WWE’s decision to choose Miami as the host city. It’s possible that Rock will also go into the Hall of Fame next year.