It being trained on eliza transcripts also perhaps explains why it's so "good" at having a conversation... sounding much like eliza.

It's actually pretty amazing how "good" eliza was at having conversations, not using anything like contemporary machine learning technology at all. That first conversation snippet in OP that OP says is "kind of scary" is totally one Eliza (or similar chatbots) could have. Weird to remember that some of what we're impressed by is actually old tech -- or how easy it is to impress us with simulated conversation that's really pretty simple? (Circa 1992 I had an hour-long conversation with a chatbot on dialup BBS thinking it was the human sysop who was maybe high and playing with words)

But I doubt you could have used eliza technology to do code completion like copilot... probably?

You're right, when you search `"what's your name" Eliza` on GitHub, you get about 8k code results, some of which include the response "My name is Eliza". But at the same time there are even more results if you try other names (e.g. 61k code results for `"what's your name" Tom`). So I still think its interesting that it happened to pick Eliza here. Possibly because repos that use the Eliza name tend to contain more Q&A-style code than others (as you mention in your comment).