I dont really think you can compare MCAT to USMLE/COMLEX. Undergrads dont use their pre med's average MCAT score as a recruiting tool. Ive never heard a school say "Our pre med curriculum is great. Look, our average MCAT is 34!" They dont do that for a number of reasons.....there are A LOT more students, not everyone takes the pre reqs at that institution, students often transfer and end up at more than one school, do post bacs, and there are often multiple options for courses at each school so even the students at the same institution have taken different pathways to finishing pre reqs etc. etc.
In contrast, a common recruiting tool and/or question by future students is "Whats the average USMLE/COMLEX." Its a legitimate question because 1) schools keep track of it and 2) it does reflect to some extent how well that school prepared its students for the boards because EVERY student is taking the same courses, from the same professors, and taking the same tests, no exceptions. Obviously, it also depends on the individual motivation of the students themselves, i'm not saying that it doesnt, but I think the USMLE definitely speaks more of the medical school then the MCAT does of an undergraduate school.
Obviously you have to pass to graduate, but I still think it matters. Part of the reason to boast of a high USMLE/COMLEX pass rate is that you can say "Look, the education our students receive is superb. Dont belive us? Our first time pass rate is 98% (which really is impressive)." Now lets say the pass rate of that practice COMLEX is like 85%......not as impressive, right? But no one sees that, because the school doesnt allow those 15% to take the test and therefore, the pass rate on the real deal (and their bragging rights) is A LOT higher. The school is then being deceptive and the prospective students are being shown statistics that dont tell the whole story.
I'm not trying to personally attack AZCOM, I have nothing against them. Obviously their students are graduating and becoming great physicians or else the institution would probably not be there. But I think its a legitimate question. And if any other schools do this (and I still don't know if its true that AZCOM does it) I think it would be fair for them to disclose the practice test pass rates too. And hey, what if the pass rate for the practice test is like 97%? Well then great! I'd still like to know. I think its great that AZCOM makes their students take practice tests and I'm not saying that they shouldn't, I'm just curious to see what the pass rate is of that test, as I would be curious for any other school that does that (i only bring up azcom b/c thats the only school that someone has brought up on another post).