They ain't pullin' the trigger on Roman/HHH for the Rumble. The Rumble itself is more often than not the main event of that show... it'd be a rush to throw that match on there- that's probably the Reigns/Sheamus wrap-up match. The whole Reigns vs the Authority storyline will still go on, and Reigns/HHH LIKELY happens at Mania, cause I doubt H is doing his once-in-a-while match at a transitional PPV. Reigns/Lesnar can happen too of course. Reigns/Cena happens probably at SummerSlam. During the summer, Reigns has (possibly) Rollins, and maybe an opponent that steps out of the midcard (Owens?).
Cena probably wins the belt at Slam...