SOURCE: Dailywrestlingnews
When asking around WWE, its said that Sting vs. The Undertaker is still up in the air for WrestleMania 31 because of so many unknown factors Stings in-ring future, The Undertakers health and more. Its said that Taker isnt even ready to begin thinking about doing the match as hes still recovering from this year.
We noted before that The Rock could end up facing Brock Lesnar at WrestleMania 31. A possible match with Rock vs. Sting has also been brought up at least once. Word is that both Rock and Sting are interested in the match but its unknown if WWE officials are interested.
The original plan for Cesaro to have no theme music was going to last a few weeks longer, as it was a Vince McMahon idea, but Triple H talked Vince into changing his mind. It was said that Triple H hated the idea of Cesaro coming out to no theme song.
On a related note, the idea to align Cesaro with Heyman was something they came up with on their own and pitched to Vince. Vince loved the idea so they went with it.