The FAFSA likely gets only a small part of the return, maybe just a few numbers. For sure it doesn’t get attachments. The info would likely have been nearly useless. Trump’s return would have dozens of pages.
I think it likely even Trump’s full personal return would have very little that was actually enlightening. The real mischief would be at least two steps further in, The business returns where Trump’s real income is generated.
There would be plenty to demagogue though. Try explaining foreign tax paid on your K-1 to someone who has never had any income from anything other than a w-2 or 1099- INT