I wonder how big free dining is?
Disney only sets aside some rooms for the free dining promotion.
Once they sell-out those rooms ..... NO MORE FREE DINING.
So you have to stay on-site and lets say that %50 of rooms are eligable for the Free Dining promotion.
Doesn't that mean that free dining has no effect on all off-site guest and maybe half of regular resort guest, who booked earlier or don't do the dining plan?
So how does it effect the 4 main parks? If only 30% of Disney Park Guest can qualify for free dining? That would mean that the other 70% of the crowd would be the normal slow season proportion that you'd normally see in September anyway.
I would guess that slow season might be inpacted by a certain percent (and the sit-down resturants packed) but total crowd levels, not as much as some might fear.