Good point, my reply didn't take it into account. It all depends on the depth of understanding, so to answer your remark consider e.g. supernatural, UFOs.

Is there really such a disagreement about Newcomb's problem?

The issue seems to be whether agents can convincingly signal to a powerful agent that they will act in some way in the future - i.e. whether it is possible to make credible promises to such a powerful agent.

I think that this is possible - at least in principle. Eliezer also seems to think this is possible. I personally am not sure that such a powerful agent could achieve the proposed success rate on unmodified humans - but in the context of artificial agents, I see few problems - especially if Omega can leave the artificial agent with the boxes in a chosen controlled environment, where Omega can be fairly confident that they will not be interfered with by interested third parties.

Do many in "modern philosophy and decision theory" really disagree with that?

More to the point, do they have a coherent counter-argument?