Not necessarily. For barn owl, night heron (and maybe pelican?), you can have a listing in natives that says the current situation, with a note saying "previously stock was imported, but this has died out, see listing in extinct exotic section for further details". Its definitely more confusing for the penguins, as the exotic stock is still present, but I think a similar thing can be done - and given Subantarctic species have already been removed, I think the King and Gentoo penguins can just be shifted to exotics and left there.