Never heard of that site before, and they didn't really cite any sources, so I'd be hesitant to trust that. Not saying it's not true, just that the research I've done so far says otherwise.
As for the Venice thing, you're not wrong, they don't exactly have a way to verify whether not they're telling the truth and that is concerning.
But again, it gets back to the whole idea of not using AI for anything sensitive. I'm all for increasing productivity with AI in different ways but at the end of the day the best thing to do when you need to ask sensitive questions is use a privacy-respecting search engine on Tor Browser or a private browser with a VPN you trust.
No perfect solution, unfortunately, but it is what it is.