Yeah i would delete the arcade platform and delete the arcade playlists, i would also after check the data/playlist folder and bin any if they are still there. All the playlist will be remade when you import your new set, as long as that box is checked at import. You will possibly also have some extra games in those playlists when you re-import as you will be using a newer set that aren't in your playlists currently, so best to clear everything out before the new import.