I have no reason to doubt you, but that seems like an imperfect system. Any system that gives weight to the USNWR ranking at all seems highly, highly flawed.
Not saying it's not real. Higher ed administrators have their own biases and whatnot, as do admissions professionals. Graduate programs may want to say they enrolled a student from X, Y, or Z University just to say that they did. I can see how it could happen.
But the USNWR rankings are trash, they've always been trash, and they should not be relied upon for any meaningful decision-making (and certainly not by people working in higher ed who should know better).