Well, the "at least for now" part is my point - if people start using "gibberish" to communicate or to hide their communication, that provides training material for LLMs to let them figure out how to use it too.

LLMs learn how to communicate based on existing examples of communication. As long as humans are communicating with each other somehow then LLMs will be able to train how to do that too. They have the same communication capabilities that we do at this point, so there's not really any way we can make a secret clubhouse that they can't figure out how to infiltrate.

Personally, I think there's two main routes we can go to deal with this. Either we can simply accept that there's no way to be 100% sure we're talking to a human any more and evaluate the value of our conversation based on the content of the words spoken rather than the composition of the entity generating them, or we could come up with some kind of "proof of personhood" system to allow people to label the text the write as coming from them.

The latter is extremely hard to do, of course, both from a technical and cultural perspective. And such a system would likely still allow someone's "person token" to be sneakily used by AI, either by voluntarily delegating it (I could very well be retyping all of this out of a ChatGPT window) or through hackery.

So I'm inclined toward the former. If I'm chatting with someone and I'm having a good time doing it, and then later I find out it was a bot, why should that change how much fun I had?