Rocco Mediate said the same thing in Golf Digest. He does not mention Rory specifically but he alludes to the "young players" with violent moves and talks about how all that torque on their back will catch up with them as they get older. He uses Fred Couples as an example of someone who had a lot of twisting and now he is paying for it with back problems.
I think Rocco's probably biased from his own back issues. His swing isn't exactly Rory-like, and Fred Couples has always had back issues. Rocco got lots of "treatment" but never really worked out, also.
Rory may have a long career. Nobody really knows.