I have no helpful advice (However, looks like you have some).

We were told a similar 96% and our ds (1st grade) was 99%. The response we got was" the group in 1st grade is really small and there's kids smarter than our ds. Next year, the group will be bigger, so if he stays 99%; he should get in" what?? Mind you, we are at public school- a good district, but still.