Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Recalibrating a Pro-M 75mm

Correct. You won't need a new MAF with nitrous as the air and fuel are added independent of the pcm/maf.
It isn't measurable by the maf anyway and the nitrous hardware comes with a way to add fuel to the shot in the correct mixture. So if that is the correct ratio, and the MAF can sense all the air the engine normally sees then you will never exceed its capabilities even if it was a 200shot.