Sure! But that begs the question why they leave it hanging this long instead of forming an unranked, stratified list that would allow the admissions office to communicate relative position to candidates (such as upper third, high priority, top 10, whatever) and would delegate final decisions to a subcommittee, as allowed under LCME rules?
Whose interests, if anyone's, are served by delaying rough sorting and voting until sometime after 4/30, when adcoms have been sitting on scored files literally for months? I'm sure it happens, and I'm sure it's because the last thing those adcoms consider important is the stress this places on WL candidates, both those with, and especially without, other As. The fact that ALL schools don't do this is evidence that it doesn't have to be this way.
Just another benefit of the seller's market. 🙂 In a more balanced market, if schools were at risk of actually losing attractive candidates needed to fill seats, I'm pretty sure they'd find a way to be a lot more user friendly, and they'd somehow manage to provide desired information to candidates in a much more timely manner.