JMO, but I think they're already screwing up Wyatt by keeping him entangled in this Cena feud. Honestly, he should be facing Bryan rather than Kane. The audience Cena appeals to is not mature enough to understand the whole "devourer of worlds" thing. The audience that is mature enough to understand it, doesn't like Cena so you're doing nothing to build Wyatt's heel status, which is what they should be doing. The older fans have made it quite clear they don't like Cena, and Cena and WWE have shown over the years they won't have him turn heel. It's like running your head into a brick wall over and over again.
Cena needs to take time away. Go do a WWE movie or focus on charity work for awhile. Do something other than swallow up time that can be used to develop newer, fresher guys that don't mind playing the heel. If/when he comes back, give him simpler heels to fight to satisfy the kids, but keep him out of the title picture. Or if he has to have a title, bring back the old TV champion belt AA used to wear.
But that's JMO.