Agree. To me alignment languages are those languages that evoke pure elements of the alignment.In any case i love the idea of aligned languages. Really interesting and plausible. I think it really adds interesting flavor and function to the structure of the multiverse.
I liken them to the scene in LoTR where Gandalf speaks the words of Black Speech at the Council of Elrond. The whole council shuttered in shock and the shadows grew. Gandalf, in D&D alignment terms, was speaking Chaotic and it had power to unnerve.