I guess you misunderstood it. It has nothing to do with optimistic updates. Optimistic updates are about rendering results that you hope will happen, like click

I guess you misunderstood it. It has nothing to do with optimistic updates. Optimistic updates are about rendering results that you hope will happen, like clicking on a "Like" button and immediately making it bold and disabled even before the request has finished. In case it errors, you simply revert to the previous state and display some feedback to the user. 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.