“While there is, of course, an argument to be made for staying on Twitter to rebut misinformation and call out hate speech, at this time the clearer imperative seems to be to take the unambiguous position that a space which amplifies such speech is a space that as a School, we will disengage from. … Twitter is not essential, only free speech is. We can leave the former and continue embracing the latter. And that is what we will do.”