I've never heard of anyone doing this either, but it is true and it's a pretty reasonable rule in my opinion. If you're an "independent student" then you don't need to report your parents' income, and the government is fairly generous about who qualifies as independent:
https://studentaid.gov/help-center/answers/article/independe.... You can definitely game some of these qualifications, but that's fine, the overwhelming majority of people who qualify for this are legitimately independent from their parents and should be considered for financial aid.