I think this article makes a key mistake that I see almost all commentators make of visions of free speech less radical than, say, the first amendment: They consider only the direct effects of speech on those who hear it. If you accept this, it's very easy to(correctly) respond that it's not the state's job to police mere offense, no matter how grave it may be. Some people who try to make criticisms of a radical free speech regime(such as the NYT author this article mentions) also fall into this trap, but I think the much more compelling for limiting speech is less about harm done by speech to listeners and more about incitement of physical harm.

It's very, very easy to communicate in ways that encourage and incite violence(be it direct physical violence or denial of the means to live a dignified life), especially against groups against whom such violence is already normalized. Not all speech that does incite violence is intended to, but this fact also lends plausible deniability to people who do explicitly want violence but know that it's socially unacceptable to call for it directly. There is the danger of being overzealous with what speech to limit, but at the same time, it's undeniable that a lot of money and attention is flowing to ever-bolder provocateurs whose only possible goal is to escalate existing tensions and iniquities to violence in service of their political aims. Taking such people at their word on their intentions is dangerous, and those who do so have no right to act surprised and claim innocence when actions and rhetoric escalate past the point they're comfortable with.