When it comes to pros I can't really buy that a wholesale equipment change can have such an effect.
With these pros, their setups are VERY well documented and any of the MFRs can provide them a set of clubs that is built IDENTICALLY to what they were playing prior. You might get slight differences in feel or ball flight, but they'll never be big enough where a professional can't figure it out in short order.
I think Rory's issues go deeper than equipment. And I don't know that they're really "issues" per se. He's young, he's had quite a few significant life happenings. I think he's really just fallen into the "enjoy life" mode a little more so. If he were to buckle down and go golf only, we'd see the old Rory return. Or maybe not, maybe he has some significant mental hurdles that have popped up.
I certainly hope he can find "it" again. He was fun to watch!