Not sure why it wouldn’t make sense - other bed-constrained schools do this. Northeastern perhaps most famously. Middlebury. Others too.
Dartmouth does it too in a way. There’s no ‘delayed start’ option but a big part of the original rationale for the so-called D plan, including mandatory sophomore summer enrollment, was to get kids off campus during the fall/winter/spring trimesters in order to increase bed availability.
Now, you can argue that schools shouldn’t accept more kids than they have beds for, but there are tons of schools that don’t guarantee on-campus housing even if they haven’t yet resorted to sending kids elsewhere to partially address this.
These schools are businesses. These plans allow them to accept more kids. By accepting more kids they are increasing revenues.