Since MOS is supposedly 100% AmigaOS3.1 compatible, the games *should* work on AmigaOS. In fact, they probably even work on PPC-accelerated classics (don't have one, so I don't know).
While many, many old AmigaOS3.1 programs work on MorphOS, you cannot run MorphOS software on anything but MorphOS.
A similar example: While MS Windows is compatible with MS-DOS, you cannot run Windows applications within the MS-DOS environment.