Just want to mention that the section on "wishful thinking" is usually called "optimistic updates" (if you want to learn more and googling "wishful thinking" isn't giving you great results).
Now, wishful thinking is about making it work even if not perfect, production-ready. It could be about rendering a hard-coded "Loading..." or "Success" or "Error" string before you hand it over to your translation team. Or just calling your param names `a` and `b` before you talk to your domain experts about the proper terms. This comes with experience.
This is not something the author invented, it's a well-known technique.