Yes I think it would be more ethical. Because it would mean that his decision had actually been changed by a specific option rather than a more general “well, I don’t know what I want to do but I just know I don’t want to be at NU anymore.”
Choosing another specific option/offer really make it “ethical,” but at least makes it a little more... maybe “explicable?”
Bet you he decommited specifically for Oregon and he will be a duck by end of next week