The Sapir–Whorf hypothesis says that language determines thought. Chomsky's theory states that cognition and language are independent systems.
Biliguals have an advantage in several areas of cognition(abstraction, task switching) (Marian & Shook, 2012).
Could this be used as proof of the independence theory. To illustrate, having to switch between languages makes you think more abstractly, subsequently you improve at this ability. Such a hypothesis would make language a layer on top of cognition, designed for communication.
Marian, V., & Shook, A. (2012). The Cognitive Benefits of Being Bilingual. Cerebrum: The Dana Forum on Brain Science, 2012. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583091/