The cold storage really is just to clear up the beer. If the yeast has done all its cleanup at a higher temperature (that's what a diacetyl rest is for,) and is no longer active, flavor is really fully developed at this point. Mind you, flavor will be improved anyway by clarifying the beer, since you're separating out dead yeast, hop resins, tannins, you know, all sorts of less than tasty stuff. But this can be accomplished by crashing, fining, filtering, centrifuging or any other means imaginable. Long cold storage is not necessary.
(The old "Märzen" lager method of lowering temperature before fermentation is complete, to finish fermentation slowly at low temperature, is just combining the yeast's flavor cleanup with clarifying the beer. This was done to keep a supply of beer coming over the summer before refrigeration. But yeast works better warmer, so it is more effective to separate the two processes: fully ferment the beer, then somehow clarify it.)