As was mentioned by Edcculus, I can see this being true for something like a weizen, but you'd be better off just fermenting a few degrees warmer than you normally would instead of messing with under pitching.
Under pitching should never really be a technique used to elicit flavours, IMO. You bring along a whole host of other issues if you under pitch, such as poor attenuation which can REALLY screw with the balance of a beer. Even if you were to try under pitching to increase ester/phenol production, there is little way to make an exact science out of it without tons of trial and error with your beer.