Earlier quoted context omitted.
My understanding is that not all of it was public posts. As an EU citizen, I can request that a company deletes my data. Unless this data dump is being treated as a crime scene or something, then the holders of this data will need some way to comply with these requests. Also, now AWS (or whatever cloud provider it is) is holding content that contains racist and/or illegal content. Are they not effectively now just an…
No, they're not. Holding a static, private archive is not the same thing as hosting a live, public site.
Now, ripping that _user_ generated data from the website this way without justified (justified = platform user agreement + legitimate interest) purpose or intent or even agreement and storing / distributing / processing it is the epitome of a GDPR transgression and borderline criminal at least in the EU (saying this as a EU citizen). They are liable. I wouldn't touch that dataset with a 10 foot pole. And I would even less brag about it on Twitter, things we do for clout I guess... :)
I have no stake in this thing, it's just to emphasize that statements like this are what get people and businesses in big trouble. Stay safe! Archive only your own data or data you gathered legitimately. Take the rest up with a lawyer or ... read the laws.