Would you object to the University sanctioning a Calvinist Club that made allegiance to the WCF a requirement for membership? Is that too exclusive and discriminatory for you?
No, I have no problem with that. I'd likewise have no problem with the university sanctioning a Catholic Club that made allegiance to Pope Benedict XVI a requirement for membership.
I'd simply object to a "Christian" club making allegiance to the WCF a requirement for membership, for the same reasons you'd object to a "Christian" club that made allegiance to Pope Benedict XVI a requirement for membership.