The llms.txt point is something I hadn't considered before but it makes total sense. We're basically entering a phase where you're optimizing for two completely different "readers" — Google's crawler and LLM context windows.
One thing I'd add: structured FAQ sections seem to punch above their weight for AI citations. If your content directly answers a question in a clean format, LLMs seem much more likely to reference it versus long-form paragraphs saying the same thing.
The meta keywords era feels quaint compared to what's coming.