This a very bold article, knowing that similar apocalyptic claims were made about Java, C and C++ over the past 15 years…
Apart from that, as pointed out by others in detail already, a large part of your claims are either wrong or exaggerated.
Then, if it comes to popularity of languages, the Tiobe index is my main reference, and I hate to tell you, but R, Go and Julia are struggling to even make the top 30 there — for as long as they’ve been in existence. The same goes for D, Dart and Scala, while Delphi still takes up a solid 22nd place, years after it’s apparent demise.
Maybe it’s time to do some more research, and replace your crystal ball with the outcome?
P.S. Java, C and Python have been the top 3 languages in that index for over a year.