Peking - I think the right to free speech is widely misunderstood. It is the right to be able to say things without imprisonment by your government for having said them (hence what is wrong with the posters on the draconian "lock 'em up on the basis of a single tweet" brigade).
It's not the right to say anything you like without having to face other people criticising your views (which may take the form of reasoned argument, or may take the form of someone saying something equally offensive in return - e.g. "saying XYZ makes you just like (insert Godwin of your choice)"). Nor is it the right to say anything you like without having to face consequences. If I say, under my real name, in a public forum like this one, "my employer is crap and does a rubbish job, and has cut corners on ABC", I can expect to lose my job as a result.
Harvard, as I understand it, is saying "we expect certain standards from our students, and if they won't meet those standards, we no longer want them as students." Where it becomes difficult in this instance is the potential clash with academic freedom. You want to be able to rule out, for example, simple straightforward racism targeting one group without banning, say, an analysis of certain religious beliefs and how they play into political and social consequences. (And a lot of the more intelligent people on the Alt Right are very adept at dressing straightforward racism up as pseudo intellectual discussion so it's extremely hard to police this boundary. Conversely, there are undoubtedly some on the far left who use "safe spaces" to shut down discussion and prevent things being discussed openly and honestly. Hence I think the worries of the law dean at Harvard - if the dividing line is to some extent arbitrary, it may be better to have a blanket "anything goes" policy - even if, in this case, it sounds like the students in question were just being little shits for the sake of it.).