It's really an issue of semantics, but it's not especially accurate to say that when you eliminate a parasitic loss, you are uncovering power that was there all along. The power isn't produced until it's produced. When you reduce windage, you are now capable of sending more power out the crank flange, if the car 'asks' for it. But it's not like there was actual horsepower running around inside the engine. To look at it another way, horsepower is measured at the the crankshaft flange....so if the power never makes it there, it doesn't count. The pistons mighta 'made' it, but it never made it to the point of measurement. It's like a bartender drinking the booze he's supposed to be selling.