I am searching for the last of the purple regional currency and can't find them. If I enter one of the little bonus areas via pipe or doorway, Cappy will usually (but not every room) hint either that there are more power moons, or that it seems there's nothing else to do here. I've never seen him mention anything about coins though. I have found purple coins in these rooms, but never took note of Cappy's remarks.
In short, does Cappy only hint about Power Moons? Or will he give a separate hint regarding any coins which may be found?