Interesting article.
Darren Siegel
1

It’s hard to find historical data for these rankings (except for the Top 20 at TIOBE). But anecdotally Scala, Haskell, and Clojure have done well.

I think interest in FP is continuing to grow. However, I believe it must plateau at some point in the future and that it will not seriously challenge OOP’s position in the IT industry.