I think it is true that many schools showed higher yield this year. Maybe speed up the process and play with CTE deadlines.
Totally, agree, as I have been advocating for moving up to a common CTE (or single school PTE deadline) in the beginning of May, while allowing total freedom to accept WL offers after that date, to eliminate the inequity of prohibiting people choosing an early CTE deadline school from participating in subsequent WL movement.
@Charmnr's observation is exactly right, but for slightly different reasons. AAMC's refusal to regulate PTE and CTE is not stopping the schools from doing so. Most are, and that's why things are actually pretty orderly, and the last minute chaos s/he's hoping for doesn't seem to be materializing. It's the lack of a MAR that forced schools to, not under accept, since seats are not unfilled, but not over accept as they have in the past. They used to over accept because the MAR gave them an accurate view into what their yield would be, so they were confident in over accepting and then allowing the class to sort itself out through WL movement, as people with multiple acceptances withdrew.
Without the MAR, schools cannot accurately predict yield, so they can't risk really over accepting, and being forced to bribe people to defer in order to get the class size down to capacity. This absence of over accepting (which really is very distinct from under accepting), then creates the totally predicable result of less WL movement, since less people are holding fewer multiple acceptances. This won't change, and isn't necessarily terrible (yes, it eliminates some student choice as it limits the ability of those lucky enough to have multiple acceptances to choose among them, but it serves the schools' ultimate objective of having a relatively orderly process that efficiently fills a class with the most qualified and attractive candidates), as long as everyone's expectations are calibrated accordingly.
Again, AMCAS, please, please, please address the inherent unfairness of allowing some candidates to participate in later WL movement but not others, by reaching a consensus on a common date to reduce acceptances held to one, and allow unfettered freedom for all to accept WL offers right up until classes begin. Last minute chaos should be avoided by encouraging schools to accelerate their WL movement to May (assuming a common date is set at the beginning of May). As has been pointed out by others, all schools as well as AMCAS, should be embarrassed that admission cycles overlap, and they can't figure out how to wrap up all movement (other than that created by last minute withdrawals) by June 1st of each year, because the process is just so darn complicated that 12 months simply isn't enough time to select a class!
Also, please consider allowing all schools to identify which of their accepted candidates are holding multiple acceptances after a certain date, in violation of their rules, so that schools can take action if they so desire in order to open up WL spots sooner rather than later. This would eliminate the ability of schools that choose not to participate in PTE/CTE from obstructing the ability of schools who choose to employ the protocol from enforcing their rules. As long as the other schools are not identified, AMCAS should avoid any accusation or appearance that it is sharing information that it has resolved not to share.