The thing is, she's not wrong about the problem. The mob is very real, and it's as un-nuanced as she suggests. I've written about this before on hubski, and was not particularly well-received, and unfortunately I think that's true in a lot of communities. (What happened to Richard Stallman is a good example of how the mob can get ahead of itself.) All it takes is one edited screenshot or just a baseless accusation and we're off to the races.
Where she is wrong is about the consequences. I can't speak to what young people may be feeling; I'm in my late 30s and have basically no shame, so "holding back" isn't remotely in my wheelhouse, for better or worse. So the idea that I wouldn't say something for fear of being "called out" is just...weird. But as for famous people, I can't think of anyone who's been permanently forced out of the public eye absent going to jail (and even then it's debatable). Plenty of famous people have been sent to time out, which I think is the appropriate response, and is better than what I was worried about; I believe that redemption and atonement are always possible.
My main concern, though, is that culturally we'll begin to forget why due process is a thing. We already seem to have forgotten that you can't only protect "some" speech (in a legal sense). Someone on a leftist discord I frequent legit said that hate speech should be illegal. I also think this is going to allow us to not give a shit about reforming the actual criminal justice system. I get the catharsis about someone who was caught on social media being racist losing their job or whatever, but we have to think about what our goals actually are. I'm not convinced that that kind of shaming will actually change anyone's mind. Meanwhile, the mob is fickle, and it can turn on you easily. We forget that our system is specifically designed so that minorities are protected (ideally, that is), but it's easy to forget that "minority" in this instance just means "someone who has a minority view." Popular speech never needs protection.