I do not believe that the article was about specific predictions and maybe not even about predictions at all. The main thesis of the article was that he was rig

I do not believe that the article was about specific predictions and maybe not even about predictions at all. The main thesis of the article was that he was right, not that he is prescient. Stallman's position has always been that it is bad for you not to have full control over the software you run. This is admittedly not very specific but I do not think it needs to be. It is a political view after all, not a scientifically verifiable hypothesis. The article enumerates some cases of that badness which were not present when Stallman started his movement but are present now. That does not make him a prophet - it is just some new evidence that supports his views.