The Bowdoin announcement is a game-changer for sure. A lot of things could have gone into the decision, but I have to believe it was something drastic and intractable for them to follow the HYPSM model. I suspect it was Coles Tower which has always struck me as an anachronism for a NESCAC: At sixteen foors, clearly the tallest buiding for miles around, it houses roughly 12% of the student body. You can imagine the potential viral load if an outbreak occured with so many students living pancake style on top of each other.
Still, it clears the way or other NESCACs to follow suit.