The Catholic Church should excommunicate the University of Notre Dame, because they clearly abandoned Christian values long ago.
You don't, however, seem to understand what excommunication is, nor what sort of institution is Notre Dame.
The two most relevant points are: (1) only an individual can be excommunicated; and (2) Notre Dame is separately owned and operated corporation, not owned nor operated either by the Catholic Diocese of South Bend nor even by the religious order that founded it, the CSC (Holy Cross fathers). It passed into essentially secularized ownership some 40 years ago. For what it's worth, its constitution and by-laws say it's supposed to uphold the Catholic faith. But there's no institutional enforcement mechanism except, really, public opinion: so good luck with that.
I'm not trying to be evasive here. I'd be thrilled to see Rev. Kevin C. Rhoades (who was just newly installed as Bishop this January) speak out strongly about it, whether he has any direct authority over the University or not.
On the other hand, a "Day of Silence" for homosexual activists is, in its way, something that has its own appeal--- especially if extended for as long as possible.