On the standard ILS to Runway 28 at Syracuse there is no Outer Marker because Radar or DME equipment is required for the approach. It does not say that on the Cat II approach but that's likely because 1) you need to have special certification and equipment to do so and 2) you're going to be under radar coverage to begin with. Thus, yes, the OM could be omitted.
Fair enough, but I think we are drifting away from my original point that prompted your reply, which was that the on-board marker lights might become a thing of the past. If I interpreted that reply correctly you stated all three markers were required for a cat II/III approach. Now you are perhaps correctly pointing out that the OM can be omitted but that was not how your first reply came across, at least to me.
That's how I always understood it, that all 3 markers were required for Cat II/III approaches, which may have been true at some point. Of course, those type of approaches are specific to the airport/runway they serve, they are all different.
As for the decommissioning of the OM, I agree 100% they will all be gone soon and the lights in the cockpit will be obsolete. It's old equipment, most of it dating back to the 1940s and 1950s technology-wise. With the satellite-based systems coming out, most of the ground equipment that currently exists will be obsolete. If it works out like the FAA wants it to, then by 2020 flying will be completely different.
Hey, at least they're not pushing for the MLS again...