My theory is that there is an initial tiny wave of few (perhaps those with a higher chance of fin aid) then the rest will come in. Just a theory considering the nature of little aid is given (?) or something is going on in the dept (shake up in faculty) that’s causing a delay.
Gee, I hope the second part of your theory isn't true...financial aid is almost equal in importance to me with actually getting in. My personal reasoning for the gap would be that international students were admitted first (as has occasionally been true in years past)...but then your friend HAD to be from Seattle, ruining a perfectly good hypothesis!