You mean the strong version of the Sapir-Whorf hypothesis is wrong. Which people like me (originally trained as a linguist) have been saying for years.
Who does defend the Sapir-Whorf hypothesis? I've never seen anybody defending it, while I've seen lots of people arguing against it; the first name that comes to mind is Steven Pinker.
The Strong Sapir-Whorf hypothesis seems obviously deficient because you can certainly think about things your language has no words (concepts and feelings, etc).
It's the Weak Sapir-Whorf hypothesis that is much more interesting and still at debate. Certainly things that are easier to describe in a language would seem easier to reason with. Our brains leverage language as a tool to map concepts and the concepts we can name are easier to grasp and utilize than the ones we cannot.
The Weak hypothesis does seem like it would be affected by brain elasticity. Keeping concepts close to hand in your language would presumably keep them easier to conceptualize as your brain plasticizes.
