It's Harvard. It doesn't matter how they accounted it, they have not changed the Tuition cost with this announcement so it's the same money and they are not hurting for students.
If I remember right, something like under 90k earned by the student's family, they pay nothing. I haven't worked there in 2 years, so the math is a bit fuzzy but the concepts are accurate.
That is only undergraduate aid applied directly to tuition. Per Note 12 on page 43, "Total scholarships and other student awards" was $613,243k, of which $457,639K was in direct credits to expenses.
That said, I don't know where the GP got the idea that most of the endowment is earmarked for financial aid. Per page 11, that earmark is specifically 19%.
as another comment points out, some of the salary and wage spend could be considered part of 'financial aid.'