It's related to this thread (
https://www.dcurbanmom.com/jforum/posts/list/1326021.page) and the schools phoning it in after testing.
Bottom line is that contractually, the schools are basically empty of staff after the last day of instruction. This means that the process of checking in the laptops and whatever the tech team/person needs to do to wipe them at the end of the year happens before the last day of classes. It means that those last 10 days are REALLY a waste of time for the kids.