As far as Facebook goes he may actually be in the ballpark. MySpace was huge for its time and then it suddenly declined when not many people expected it to. Everyone jumped ship to the next big social media boat. I have actually been watching my friends, one by one, deactivate their profiles on Facebook. Now obviously that is such a tiny sample size but these people jumped on Facebook from Day 1 and loved it. Now they just see it as nothing more than a cesspool of memes, advertisement, and people who never went to college acting like Facebook is the place to put their imaginary degree to work. I see a lot of the same garbage plastered all over Facebook that I saw on MySpace when it spiraled out of any relevance. It's not as sloppy but it's there. As other means to stay connected with friends and family have increased and improved the hook of Facebook has dulled. Three years may be just a little too soon but I would not be surprised at all if by 2020 that website is nothing more than a memory.
Microsoft vanishing soon? Not going to happen. They are far too deep into the computer and electronics world to die off so quickly. Could Microsoft become less of a force in the world? Absolutely, and I suspect it will happen sooner than most people want to believe. However, I see them around for quite a few years to come in one way or another. Google is actually the one company he listed that I suspect is going to continue its upward trend and I even suspect that it may replace Microsoft in the world of PCs. In fact, it may very well replace a lot of currently dominant companies in various fields of electronics. I think one thing is almost certain, though. Whatever the picture is of the computer world today, it will look a lot different in 10 to 20 years. A lot of today's major players will likely end up as tomorrow's history lesson.