I think the title was (perhaps intentionally) overstated, but the content of the essay is correct. The better title (in the sense of more accurate, perhaps not for getting clicks) would have been "Microsoft Is The New IBM". And that is still true.
IBM is 20x smaller by market cap, 4x smaller by revenue, they are shrinking organically because they forgot how to make anything and no one starting any business from scratch would use any of their products.
He got it completely wrong. It is what it is. If you comment on enough things you are going to be very wrong sometimes.
PG was referencing pre Nadella Era.
IBM doesn't move like this, even if those are acquisitions.
Microsoft is very focused on where the money flows, and they have adapted to the change of times.
While Ballmer built a solid cash foundation - he would never have done a move like Linkedin or Github acquisition. And I would not be surprised if Github acquisition was a part of the plan about AI.
Microsoft was never this far gone. PG was proclaiming their death because startups no longer feared them. But they no longer fear Google either, not the way they used to. Google's last truly disruptive and unexpected projects - Android, Chrome, Maps, Docs, etc - happened 15+ years ago. Now, the company sticks to established niches instead of trying to constantly reinvent themselves (or when they try, they almost always fail).
There's a spectrum between "dead" and "taking on the world".