Unless I am missing something, it should not be a problem to remove the 3rd language from your DS' schedule if you provide explicit authorization not holding the school responsible. Your school already has a policy of exempting some students from a 3rd language and your DS has a medical opinion specifically exempting him. It may be an issue of the school protecting itself against future complaints from parents who felt their children were cheated out of the full curricular experience or whose children end up not comparing favorably against classmates who complete the full curriculum.
