Eh… The blog post left me hungry. He doesn’t talk about his experience per se.

OneDrive even silently reinstalled itself and moved one customer’s data to the cloud, all without consent. One day their data was on the local drive and the next it became online-only files that had to be downloaded from Microsoft’s servers.

External party (microsoft) uploaded some unknown code to user PC (hidden in update) and that code uploaded and deted all that data.

That sounds like stealing + (almost) ransomware?