Sounds like Universities are now becoming lackeys for the Federal government. These days, the vast majority (80% - 90%) of student loans come directly from the Federal government. Private lenders were taking advantage of students, so the government stepped in and pretty much owns the market. And the government won't generally let you off the hook for these loans -- even through bankruptcy. The government wants its money back.
The same government that subsidizes student loans also sends grant money to the Universities. I'd bet dollars to donuts that the government is willing to put the squeeze on universities to find some way to force students to pay. It shouldn't surprise anyone to find out that the Feds might withhold funding from Universities if their students don't pay back loans.
Like the summary, and others, have pointed out: there's no good incentive for Universities to not send transcripts for students behind on their loan payments. So why else but pressure from the Federal government would Universities do something that harms their alumni and their reputation?