When I reading your post I was assuming that between the first and second year of this program could be the biggest risk to seeing a decrease in donations. If it is a small enough number then it may be statistically insignificant. If the number is significant (regardless of the levels), then I wonder how many of them would/could use your logic even though a part of them may be upset they had to overpay for their seats.

For the people, who feel they overpaid for their seats, then they could react 1 of 3 ways:

1. Give more and hope they move up the ranking enough to be able to select in a better section.
2. Feel lucky they were able to get the seats they got the past season. They could opt to give more in hopes that fewer people ranked below would surpass them or continue giving at the current level and hope they don't move down the rankings too far.
3. Reduce their donations to reflect the current value of their section and hope they don't move too far down the rankings so they could keep their current seats.