I think you mean no school is truly need blind and meets full need? (Because, most public schools are need blind but don’t promise to meet need for everyone).
I understand your point, but I don’t quite agree. The number of students that need aid doesn’t vary very significantly from year to year at these Ivies (look at section H of the CDS). And these schools can comfortably manage that variance because they have such large endowments. So they don’t need to actively manage the number of enrolled students whose need they have to meet.