To share is to lose control. You can't undo, even once shared, it can't be undone. You can't retract a published novel. You can't retract a broadcast music or show. What makes you think you can do it over internet?

I don't think my article makes any claims that one can undo sharing. What I'm saying is that we benefit collectively from being able to untether data from applications. It's the same logic as https://stephango.com/file-over-app but applied to the aggregating web applications.