Back in the pre-digital dark ages when feudal lords ruled the forests, and dinosaurs had only recently become extinct, the NBME had a statement in its bulletins that the USMLE scores were not useful in providing applicant discriminant information and that residency programs who tried to use the score were abusing the exam. That is also the reason they disallow retakes on the exam.
I just looked at the USMLE/NBME sites and see that they have dropped all pretext of this idea. When I was asked by a very prestigious program about my score, I quoted the USMLE statement and said I passed.