Yeah, a lot of people, commentators, HNers, Redditors invoke US laws and procedures as reasoning and for comparison. Which is bordering on the useless - okay, you think he wouldn't have been arrested in the US, cool, what does that actually tell us about him being arrested in France? Nothing? You didn't even bother to look up how warrants and arrests and criminal proceedings work in France? Thank you for wasting my time with your commentary.
The article was written for the benefit of Americans with business operations in France, so understanding why America is way better than France to run a social media company is relevant information.
That the article wound up being circulated to a bunch of Europeans who thought it was an article about French law after someone posted it on HN is something of an accident; the article isn't for them (unless of course they're planning on starting a social media company, in which case leaving Europe and setting up shop in America on a permanent basis would be recommended). The very fact of his arrest is enough for Americans to know to steer clear of the EU going forward.
There is plenty of legal background for France (and Europe more broadly, eg the German NetzDG) there if you'd care to read the piece, including reference to numerous censorial provisions of French law which make France suboptimal vis a vis the U.S. for social media operations including Loi no. 2020-766 du 24 juin 2020, the EU DSA, and the applicable French aiding and abetting statute, the last of which would not have been usable against Durov in the U.S. absent specific intent to commit an unlawful act.
The conditional immunity under the DSA is also not as comprehensive as the broad immunity under Section 230, but that was out of scope so I didn't get into it. I do admit the piece assumes some familiarity on the part of the reader with the existing problems around the EU regulatory schemes relating to speech and content removal.
If you have any constructive suggestions I'll be happy to consider including them and giving you appropriate credit, just chuck them in the comment section. tl;dr though, in my view, France is not a great place to incorporate and run a social media company.