Hmm, but did they say the last version of Windows, or the last version of Windows you're going to buy? And if it's the latter, is the upgrade to Windows 11 free? If yes, then technically it's still correct.
I mean, that was back when if you wanted a home computer, you were building it yourself from parts from Radio Shack. Not exactly the same thing. I'm not certain that even Apple had the Apple 1 out at that point. I know they hadn't made the Mac 128k, and weren't going to for several years.
I haven't ever met anyone that thought Bill Gates was prescient, just a lucky businessman.
He was asked what they are working on now that they released Windows 10. He said they are still working on Windows 10 as it's the last (latest) release of Windows and still being developed. Yes he could have worded it better.