Private University Financial Aid office requested my parents 2016 tax return for 2017/2018 WHY??

Private University Financial Aid office requested my parents 2016 tax return for 2017/2018 school year after I submitted my CSS Profile and my 2015 tax return??? Why ??
2017/2018 school year suppose to based on 2015 tax return so have real #'s earlier and don’t have to wait for completion of 3016 taxes - I told my parents this so they didn’t have to rush doing their taxes again since they usually request extension and complete taxes this summer - but now financial aid office requesting my parents 2016 tax return so this was even more work than before since now requesting 2 years parents tax returns!! Now my financial aid application will be delayed at least until middle April /May 2017 for my parents submitted 2016 tax return!! Not good!
Has anyone else had request for 2016 tax return for financial aid ??

Since this would be for determining need based grant awards from the private university itself they have a right to request it. Also, something on the 2015 tax form may have raised a red flag.