Cornell don't rank their wait list, so I would guess that it's based on AOI. They have six places but make more than 6 initial offers, because they expect some rejections. The number of extra offers is based on trends from previous years. So they expect to make 0 offers to people on the wait list. However, last year they made at least 2 offers to people on the wait list. Unfortunately, that might mean they sent out more initial offers this year.
Cornell is my first choice, but I am on the wait list. Alas.