I don't know about that. He looks better than 99.9% of the roster. Once he starts doing cardio steadily he'll be ok. Trust me when I tell you that he WILL carry the match with Cena (if it even happens).
There's a little more to "ring-shape" than leaning out and doing cardio.
You've got to "bump" train, as well as practice drills and rehearse spots - stuff every trainee goes through.
Amazingly, your body becomes conditioned
(to a degree) to falling/landing, but if you haven't done it in a while...look out!
Rock's been away for a long time.
Still, he's not starting from scratch, and I suspect it'll all come back for him fairly quickly.
And, I don't think he'd return in a shape that would disappoint the fans.
I fully expect him to look good & move well.