I think non-RLHF'd LLMs (i.e. pretrained text completion models) sound natural enough to pass the Turing test, but I don't know if anyone has tested them for that. (Also I'm not sure how to come by base models without post-training crap, even the "base" models of recent releases start spamming assistant-type text constantly, i.e. they're clearly putting it in the pretraining data.)
If I'm right on that then we hit that benchmark like five years ago.
The egg thing, probably 2030-ish.