For some instruments, such as keyboards, Finale 2012 and later automatically loads the correct patch from IO. However, since IO is a unique library that is mostly mixtures and blends rather than individual instruments, most instruments in Finale will not have a corresponding patch in IO, and vice versa. You can set up blank staves and assign the IO patch you want to use in either the Score Manager (Window > Score Manager) or by opening an instance of the ARIA Player from MIDI/Audio > VST Banks & Effects (Windows) or MIDI/Audio > Audio Units Banks & Effects (Mac).