Yea, the article did allude to some retirees being in the dark about the loan being in arrears. At the same time, the DoEd said that anyone who is getting their SS check cut back hasn't made a payment in probably at least three years. DoEd tries to collect for two years, then they send it to a collections agency which tries for another couple months before they send it off to the Treasury, which then makes two additional attempts at collecting. That's a pretty long process, and I'd assume that at some point in there, the (soon-to-be) retiree should probably ask the kid/grandchild benefiting from the loan to explain what exactly is going on.
But the bigger story here is that apparently retirees are expecting a majority of their expenses to be covered by SS, so this 15% haircut sends them skidding downhill. Quite honestly, someone who is either living such a high lifestyle/so leveraged as they knock on retirement's door that they can't handle a 15% deduction in income probably isn't really ready to retire anyway.