That would actually be an interesting idea to pursue because I don't think it's even decidable and may require an AI/human to write back to understand. It depends on context that may not even be there. (Think of the absurdity of chain-comment-memes on Reddit, for example. The question may not even be answerable until lots of other people have replied. Now, you may not permit that as "grammar", but it speaks to the complexity of even defining grammar. Words are repurposed, etc. etc.)

Maybe... just maybe memes could be the key to AI /s