You haven't researched that much, then, or you've been reading website articles that are a few years old. WDW attendance patterns are changing, in part due to all the families who now take their kids out of school. We've been the last two summers, and had low-moderate crowds. Meanwhile, fall & spring crowds have gotten heavier. As for the prices, check the difference between midsummer & fall prices/availability, or the difference between midsummer & spring prices/availability. It's the truth. Midsummer is now cheaper & less crowded than much of the school year.
The WDW weather also won't be any nicer in early September than it is in midsummer.