...I lived in my dorm (Morrissey) all 4 years. A lot of seniors went OC, but rather few juniors. I can't even remember one.
If lots of juniors (or sophs) went off campus each year, you could construe this as a forced-placing of room and board fees on students; and I'm sure, at any rate, that they have run the various numbers. One underlying thought must be: we've spent $$$$ building new dorms and renovating existing ones--we don't want a bunch of vacancies. But unless there have been significant numbers of juniors moving off campus, this seems like no big deal.