This is good, important information. But it also leans into fear mongering (as this author tends to do). Everything online, save for E2E encryption to a single party you trust completely, has always been public. No law, or third party has or ever will change that. It was fiction to believe it existed with Facebook, it is also fiction to believe it exists anywhere else, including GDPR. This was common knowledge in the late 90's. Have we forgotten so quickly?
And let's not act like this is all so obscure that common people can't relate. You have no privacy the minute you leave the confines of your house. Shout something obscene in a cafe? It's on full display for everyone to see and video.