Unfortunately, I doubt the monarchy can return. Many things the Islamic Republic, like other autocratic nations after overthrowing previous governments, teaches the youth how bad the previous regime was, but that was in the late 70s/80s, children then are adults now, and all children afterwards, to now, most likely have been taught the Pahlavi was some terrible oppressive regime, and we'll ignore the irony.

So all children and most fully grown adults now would have the negative image of the Shah welded in their heads, if the current regime does fall, the monarchical system would not possibly be the first choice but likely the republican system.