I'm not an expert on the dT/dt solubility rates for different compounds. The basic coffee literature I know has no serious discussions of the chemical thermodynamics of brewing; quite possibly because there are too many compounds. However, I do know that the characteristic cold brewing or toddy coffee flavor comes out when you brew below about 85C (185F), both for regular brewing and for espresso. At this point, the acidity drops of too, and all you get is the malty compounds and the sugars (along with the caffeine).
If the coffee is poor, this might be a good idea. For instance, I think one of the reasons the Nespresso system produces fairly pleasant and understated shots (but not good ones), is that it brews at these lower temperatures. But for good coffees, you are leaving out all the the things which differentiate great coffees from mediocre ones.
I do a coffee seminar with a group of UC students every year. This year, instead of the usual Folgers, I demoed the Nespresso system to show how far mass produced coffee had come since the days of instant and Folgers cans. Everybody there (i.e. people who like coffee but aren't experts) found the straight Nespresso espresso shots pleasant (unlike the previous years' Folgers, or sadly the bulk of US cafes), but simply not in the same league as the good coffees I was brewing.
So my take is that cool brewing temperatures goes along with capsules and other technologies that make for pleasing mass produced coffee. It's a lot better than awful mass produced coffee, but still nothing like good coffees prepped in ways that bring out their distinct flavors.