The missing piece seems to be that for certain questions it doesn't make sense to extrapolate, and that if it's a question about what will happen in the future,

The missing piece seems to be that for certain questions it doesn't make sense to extrapolate, and that if it's a question about what will happen in the future, it should answer in a different manner (and from my own interactions with ChatGPT it does exactly that, frequently referring to the cut-off time of its training data).