I’m not sure I follow. What if LLMs are helpful but not useful to AGI, but some other technology is? Seems likely.

The comment wasn't referencing LLMs, but generative AI.

Even then, given the deep impact of LLMs and how many people are using them already, it's a stretch to say LLMs will have no effect on the development of AGI.

I think it's pretty obvious that AGI requires something more than LLMs, but I think it's equally obvious LLMs will have been involved in its development somewhere, even if just a stepping stone. So, a "precursor".