Don't know if it was a "surprise" per se, but I doubt Jay and staff pushed him out. He has a solid rating and projects as a mid round pick. Probably more than anything just wanted to play for his dad. It was always kind of bizarre that he committed here in the first place instead of Northeastern.
Keefe didn't sign an NLI back in mid-November when the rest of BU's '06 recruits (Eiserman, Hutson, Bednarik) did, so this switch didn't come as a surprise. My guess is that Jay and Joe have a plan B, which likely would include signing a veteran defenseman in the transfer portal as BC did with Bengston and PC did with Krys.