Japan also tends to leave many contextual and obvious things unstated, and relies on group concensus and information exchange between in group peers over top down authority, so may consider the ultimate group concensus, language, not needing to be codified.
Although i do wonder what my son's 国語 text books teach if Japanese is not the official 国語.
Although i do wonder what my son's 国語 text books teach if Japanese is not the official 国語.