> My German isn't good enough to read the original text about this case, but if the sentiment behind https://natlawreview.com/article/data-mining-ai-systems-trai... is correct, I wouldn't be surprised if this would also fall under some kind of legal exception.

That's something completely different. One is about copyright of stuff that was shared publically, while the other is about sharing private communications, violating their personal rights (not copyright).

But of course, we'll have to see, I'm not a lawyer either.