Per my conversation with admissions, all GA positions have been filled. Merit based financial aid includes Assistantship opportunities. You would have to ask about Research positions, although you would be competing with current Wagner students for those.
Since Wagner is government and nonprofit focused, they seem to not offer significant funding for many incoming students because they know you can enroll in the Public Service Loan Forgiveness Program (PSLF). As most of you are aware, you take out Direct Federal loans, pay back through Income Based Repayment (IBR), PAYE or REPAYE program and make 120 payments over 10 years to have the rest of your debt "forgiven". But you must be working at a non profit org or local, tribal, state or federal government.
Hence why they advertise PSLF under the financial aid page of their website. Although for many thats a tough pill to swallow. Being in debt for 10 years is no joke.
For many applicants it seems, the "check back with us" financial aid form may weigh heavily in accepting or declining the offer of admission. They have stated updated financial aid offers will be sent out no later than April 20, 2016.