I have a theory about that.
While reading the U.S. News rankings I found an old quote cited to the RVU dean in which he stated high MCAT scores are highly correlated with students who move on to more competitive specialties, instead of primary care. When people on here or other places talk about rankings they are often referring to the U.S. News rankings. The only ranking D.O. schools show up on is "Top Primary Care Schools". So if RVU wants to one day say they are ranked highly by the U.S. News, they need to really push their students towards primary care. So I think, putting my tinfoil hat on, that RVU has an unspoken strategy in place to select students who will score in a sweet spot on COMLEX/USMLE where they're just high enough to pass, but not so high that they will be eligible for competitive specialties. I suspect that their admissions policies are centered completely around the profile of a student who will most likely go into primary care.