Coasting doesn't just refer to grades. The first two years just lay the groundwork for the clinical sciences and journal reading...
You will really start to see a gap between students when you start 3rd year clinics. Clinic is mostly pass/fail or a pretty easy "A" or "B" if it's graded, so you can do as much or as little as you want on most rotations. Some people will show up early, grab chart after chart to see as many patients as they can, ask good questions, and go home to read textbook chapters or journal articles. They'll read about stuff they saw in clinic, were asked by attendings in clinics, or are just wanting to learn for personal, research, or residency interests. On the other end, some people will show up late, ask for days off or early dismissal, skip classes, read the minimum, etc. GPA in the early years is important, but it's not the only thing.
As for AZ's pass rate, it's good so far, but the first group of test takers was only 12 or 13 people (weeded down from 25 or so?) and I'm not sure the size of this past year's group? Also, nobody there has even taken pt2 yet. It's great that the program appears strong in early measurables, but keep in mind that they're on their best behavior to get accredited... it might not be the best idea to start bragging just yet. Once AZ's pod program gets full approval, class sizes will start increasing while attrition rate goes down, and that'll be the real test to see if the school can stay on par with DMU and Scholl in terms of board pass rate with bigger classes. Nonetheless, I applaud any pod program where the students are in classes with MD/DO students. That should largely prevent the excessive curving that some pod schools would otherwise do, and it should prevent unqualified people from graduating. Qualifed or not, some people are still just lazy or will always do the minimum, though. Many of those people are smart enough to pass, but it probably doesn't make them good docs or ones who will be getting six figure job offers...