Surely the same applies to Omega. By hypothesis, Eliezer knows that Omega is reliable, and since Eliezer does not believe in magic, he deduces that Omega's prediction is based on good evidence, even if Omega doesn't say anything about the evidence.
My only reason for being unsure that Eliezer would one-box against me is that there may be some reflexivity issue I haven't thought of, but I don't think this one works.
One issue is that I'm not going around making these offers to everyone, but the only role that that plays in the original problem is to establish Omega's reliability without Newcomb having to explain how Omega does it. But I don't think it matters where the confidence in Omega's reliability comes from, as long as it is there.
If you know that Omega came to a conclusion about you based on things you wrote on the Internet, and you know that the things you wrote imply you will one-box, then you are free to two-box.
Edit: basically the thing you have to ask is, if you know where Omega's model of you comes from, is that model like you to a sufficient extent that whatever you decide to do, the model will also do?
EDIT: I see by the karma bombing we can't even ask. Why even call this part of the site "discussion?"
Some of the classic questions about an omnipotent god include