They really shouldn't though. They should learn their lesson with Batista.
If a guy isn't ready, he isn't ready. Don't care what the long term plan was, they should go with someone else but make him look strong in the process.
In general, the Rumble needs some sort of unpredictability, because knowing the winner gets the WM slot means every year you have a max of three possible winners.
Personally, I'd give it to Ambrose. I'd then have Rollins cash in MITB on Lesnar/Cena, and have Reigns win the strap off Rollins at Elimination Chamber. That'd set up Reigns champ, Rollins rematch and Ambrose as the Rumble winner for a three-way main event with The Shield members for the title at Mania. At least that way, Reigns isn't booked to the moon but the end result is achieved, and you elevate three guys at once to main event status.
