Some of the preliminary work is making sure financial aid applications are complete and that any supplemental information needed is received. This then makes the job of completing the financial aid package quicker.
Even IF the financial aid and admissions folks are in the same room, do you really think the admissions folks at need blind schools have time to yell over “hey can you tell me what the finances are for Susie?” They don’t.
At need aware schools, the financial aid department provides the level of financial need to admissions. Because level of need is considered at these schools at least for some applicants.