We were there last year during Labor Day weekend...MK was quite busy compared to the week earlier and MGM was REALLY busy because of the Tom Joyner family reunion...I think they hold it at that park specifically. Now, that being said, we've always gone to WDW in off times so what seemed busy for us probably isn't really!
If so, that could explain the low crowds.
I was hoping to stay until the Tuesday or Wednesday after. However, our Mayor decided to have school start on Tuesday instead of Wednesday or Thursday.

Cindy