An important feature of WhatsApp is that it lets you communicate with different people, who each have different pre-existing contexts and roles for you. Role selection is one of the possible solutions proposed in the article.

The blinking cursor is a metaphor, it's about having to craft prompts and what that implies from a UX perspective.

I tend to know people on chat are human and therefore what they’re likely capable of and not capable of.

And I’m not expected to use them as a tool. By contrast I can probably pick up any Ryobi power tool that I’ve never seen before and work out how to make it do its thing, and probably what its purpose is