Yes, what is interesting is that the overall average for LM scores has no changed all that much over the course of the decade, but the change in LM matriculant distributions at a handful of schools has been insane.
I don't think schools have really suffered in any meaningful way...I suspect there was a very big push from the top (Deans of Admissions and up) to push USNWR ranking as high as possible. In order to do that, you basically have to do two things, assuming the actual quality of your school is not changing over a short period of time: 1) push your selectivity metrics as high as possible (get more and more people to apply, only accept people with the highest scores), and 2) have a lot of research $$$.
2 happens at an institutional level, but 1 happens at the admissions level. For schools like UCLA, UCSF that have not changed their stats very much over the course of the decade but stay at the top of the rankings, you have a situation where their average numbers were already near the top of the pack a decade ago and they just havent followed the arms race as aggressively, likely because they are already such well established institutions that their research $$$ alone could sustain their "high rank" status. U Wash is a bit more unique in that there is heavy in-state bias at that school so there can only be so many Washingtonians, but beyond that it is extremely well regarded as a research institution and has a lot of research $$$, hence they can keep their #8 spot in the research rankings without resorting to WashU level number whoring.
This explanations works when you consider how quickly Vanderbilt and NYU have risen in the rankings at both the undergrad and medical school level pursuing this same type of strategy while the institution itself remains practically identical. Certainly, it has resulted in a boost in prestige from ranking alone, even if, as
@efle has demonstrated elsewhere, their medical school graduates are still not has highly regarded by residency PDs as graduates of places like Baylor and Mayo which have spent a long time in the "tier" of rankings Vandy and NYU now occupy.
But there's a problem with this explanation. Namely,
why the hell would schools like WashU, Penn, Columbia, etc follow suit in this arms race? Their research $$$, renown, and attachment to brand-name undergrads should be enough to sustain their rankings and their prestige (i.e. make them attractive places for donor $$ and good applicants to apply to). While Harvard has not shifted their stats upward by as an incredible amount as others,
even if they had a matriculant average LizzyM of 1, their research endowment is so incredibly obscene, their associated hospitals so wealthy that they would still be number 1 in USNWR even if HMS itself were only a collection of boxes and duct tape with lectures entirely written in Braille. They have no skin in this numbers arms race.
From earlier discussion and evidence ITT, it is obvious this process is admissions and not applicant driven. So, we should take a look at those schools in particular more closely.