Nonsense. Extending a language to denote new concepts is easy. You can borrow a word from another language (ennui, schadenfreude); you can repurpose an existing word (broadcast, which once meant to stand in your field and throw seeds in every direction); and you can coin a new word (Twas brilling, and the slivy toves / Did gyre and gimble in the wabe).

The Pirahã don't have words for concepts that fall outside their cultural worldview for the simple reason that they have no need of such words.