The mentioned paradox is simply not true. How would being fluent in Haskell make you appreciate the need for assembler programming in, say, math opitimizations in Go crypto packages, or any low level stuff?
I would like to hear this claim with more specificity, like if the claim is that learning Clojure will help you predict how the language atoms of Go might lead to some structures, or more narrowly that if Clojure has more supported concurrency models, then it helps you judge Go vs Elixir from a concurrency perspective, or if learning a multi-paradigm language helps you judge a language with a paradigm focus.