The inside story is that the new Dean of the School of Art is a terrible administrator and as a result most heads quit.
The old head of the photography graduate program complained about the poor treatment the sculpture head and others received; he was fired, others quit. I've heard directly from one senior person directly involved that the Dean is impossible to get along with, despite the seemingly "nice" and "bookish" appearance, and he directly caused the exodus. This is a shame since it represents complete dismanteling of one of the top art schools.