The arguments that the kind of speech referred to in the article is worth defending are really weak. Sure: there is no question that free speech
in general is a useful tool in increasing transparency and thus public enlightenment - thus protections
in general aren't in question. Yet the defenders of absolute or unconditional protection repeatedly - as in this article - make remarkably poorly supported claims.
The first poorly supported claim is that because it's supported in the US, it's worth supporting. This is just weird; frankly. If US laws were perfect, society would be a lot more stable, and you might as well abolish congress. Clearly, laws are not perfect; and where there are regional legal differences, you should not assume the US protections make sense - nor in fact that either approach makes sense. It's frankly irrelevant what US law is on the topic of what protected speech should be.
The second, and more fundamental error in reasoning is that somehow a slippery slope applies, or by extension that you can't expect a court (or other control mechanism) to be able to tell harmful speech from constructive speech. Obviously, there will be some corner-cases where decisions will be essentially arbitrary - but that applies in any system, including the US. But what's not at all obvious is that those close calls actually happen very often, nor that they matter much when they do. There's usually wide, clear distinction between what's essentially malicious deception (as in this case) and possible truths that deserve protection. In practice it just doesn't happen all that often that something is possibly both. Here too: you could argue whether or not the posts in question are harmful enough to deserve a ban; but there's no argument that they were truthful and worth protecting; they clearly were not. To summarize: the idea that legal controls on deception or defamation will to a meaningful extent do collateral damage to free speech which increases transparency simply does not appear to be true. Sure, a despot could do both, but a normal society can choose not to do that just fine too.
The third (implicit) reasoning flaw is that what we have today is actually free speech. This misunderstanding rests on several pillars. Firstly we should not ignore harms caused by libel laws, especially in a country like the US, where legal costs can be punishment alone, regardless of legal victory, and where legal standards differ by state allowing jurisdiction shopping. Secondly, we should realize that speech needs protection from power in general, not specifically government alone. Much later modern-style free speech developed into a roughly modern form, corporations evolved. Corporations may deserve some protection from the government, but they themselves wield enormous power too, and speech needs protection from their interference too. Finally, the protections we do have are quite... abstract. They're not sufficient to protect speech in practice, not by a long shot - just witness how abominably whistle-blowers are treated. Rather than the essence of communication and transparency being protected, we protect technicalities. We may not technically live under a massive censorship regime, but that's just because we've interpreted self-censorship and corporate control as being something fundamentally different - and that's dangerous, because we're not protecting speech as some kind of academic exercise to create aesthetically pleasing laws; we're doing it to protect public discourse and transparency. And we're not doing that as is.
We really need to move towards a healthy debate on free speech itself. The principle is clearly sound, but our implementation of it is equally clearly not sound. And that holds true just as much in other countries; this isn't some US-specific problem - because pretty much anywhere in the west it's OK to lie about (say) vaccine dangers without any repercussions even though evidence-free conspiracies of that kind do real harm to everyone in society. Yet if you defame someone - just one person! Well, that's apparently not OK, we need to protect individuals from libel? Even if there's any sense in that (I doubt it), it sure doesn't appear to do us much good regardless. There's a reason why e.g. plutocrats such as Putin thought it was worth interfering in foreign public opinion: precisely because he thought freedom of speech does not work well in the countries he tried to manipulate; freedom of speech would not prevent malicious lies from spreading through the public. And you know what? Putin's right.
As such, while it's fair contrast the US approach to that of others, I think doing so is akin to worrying about really marginal issues (e.g. exactly where to draw the line between defamation of a politician vs. protected opinions about that politician just doesn't matter much: there are lots of possible lines, and most are just fine). The more fundamental issues are broadly similar - and deeply unhealthy - in all western countries.