Not your imagination, he did say that. More on that later... I have some plans.
Worth mentioning it is not possible to promote someone to expert in only one section, because all three sections access the same database of users. As above, you can still earn editing powers on a section-by-section basis.
Adding new ranks would require custom code, though. I know there are some other features in Q2A that can give users a similar distinction. I’ll mention them at some point down the line. Not sure if Pokemaster likes them though, seeing as they don’t already get used.