Many approaches that don't have VNAV/LNAV minimums published, are still encoded in the database....however in FBW bus...(dont know about the A300) it is prohibited to fly these in Final Approach mode
That may be the rule in your neck of the woods but it isn't universally so. With certain restrictions, many jurisdictions permit the use of the fully managed NPA without having an LNAV/VNAV minima published.