Hockey East just extended Joe Bertagna's contract for three more seasons. While it is possible that BU, BC and one or two other schools voted against his contract extension I think that is unlikely. Furthermore, he has stated many times that he wants to expand Hockey East to 12 teams and a 22-game league schedule. Therefore, I think it is more likely that Hockey East will become a 12 team league before any teams split away.
As for Notre Dame, if I recall correctly the statement was that they preferred to be part of a 7 team conference with a 24-game league schedule as that would allow them to schedule 10 non-conference games with BC and B1G teams, among others. A 12-team HE with a 22-game league schedule (including 2 games vs BC) would allow them to schedule 12 non-conference games against B1G and other teams. And as I posted previously, if WMU joined HE as the twelfth team it would give Notre Dame a travel partner for league play.
Sean