Absolutely. This is useful but it is highly unlikely that any of the languages in this chart will disappear anytime soon. As I plan my learning-time investment budget for the next few years, it's only marginally interesting to me that blockbuster language Number 2 goes to Number 4 or whatever. I already know that any of these languages would be a good choice as long as they fit the applicable domain.

What matters much more to me is that language number 40 suddently find itself at 20, for example. To really plan for the future we need to peek at the nascent trends in small-language land. I'm much more interested in Ocaml, Julia, Nim, Rust, or Lua, even Cuda, OpenCL, Chapel or Cilk, than I am in Python, Java/script, or (sigh) CSS.