John Cena is the No. 1 contender for the WWE World Heavyweight Championship and appears likely to challenge Brock Lesnar at WWE TLC in December. Cena beat Randy Orton at Hell in a Cell with the stipulation of No. 1 contendership being added. To unpack the creative plans, we need to go back to a WNW Premium report on September 25, 2014.
At the time, Vince McMahon had been going back and forth on whether to do Lesnar vs. Cena again at Hell in a Cell or keep them apart for a little bit longer and blowoff the program in the main event of TLC. There was also talk of doing Cena vs. Lesnar at Survivor Series and then doing a triple-threat with Seth Rollins at TLC.
The reason it looks like Cena won't challenge for the title until December is because Brock Lesnar isn't featured in the first Survivor Series commercial. We have other evidence to suggest Lesnar will be held off TV a bit longer, but nothing has been confirmed as of this writing.
All and all, Vince wanted to do Cena vs. Lesnar III (technically IV) to blowoff the program but the stipulation added to the Hell in a Cell bout was done to appease Randy Orton, giving him co-main event status.