Well you are asking a question that you already know the answer to. The MAF sensor does not attempt to know this part of the equation, it is not a function of that form of air metering (this is why a air fuel controller is needed-to fine tune your system...with your turbos...and your intercooler...and your altitude). The problem is the Intake Air Sensor is a VITAL part of a MAP sensor (1/2 of its functioning components in fact) and when it becomes heat soaked, all the tuning done at one level is now skewed by this incorrect reading.
I would like to point out that I am not pushing the stock setup-or to change to a MAP sensor setup. I think both have their merits and their faults. I was just trying to share some info I was lucky enough to come across with others.