The appearance is being framed as Cena returning to celebrate 20 years since his main roster WWE debut but there's been talk of him wrestling at SummerSlam next month.
It hasn't been confirmed by the company but it was reported in the Wrestling Observer Newsletter that there's been talk amongst people in wrestling that Cena and Theory will set up a match for SummerSlam and the idea is to elevate Theory to a higher level.
It's no secret that Vince McMahon sees Theory as someone who can become a WrestleMania headliner. Theory and Cena have been going back and forth on Twitter in recent days and Theory has stated in interviews that his dream match would be against Cena because he idolized him while growing up. Both have even been seen in photos together.
Theory is the current United States Champion so the match with Cena would have the title on the line.