Here's an example of inconsistency in philosophical use. I keep saying that Eliezer equivocates about whether he is a realist, and that I think he's right to do so. Elsewhere in the comments on this post you say that moral subjectivism is not realism by definition. But it's not clear to me from the Stanford Encyclopedia entry on moral realism that this is so. The entry on anti-realism says that Sayre-McCord explicitly puts moral subjectivism in moral realism. Since he wrote the article on realism, that explains why it seems to accept that possibility, but this it certainly demonstrates that this uncertainty is more mainstream than you allow.
The problem with the standard jargon is that "realism" is used to label a metaphysical and an epistemological claim. I like to call the epistemological claim, that there is a single set of moral truths, moral objectivism, which clearly is the opposite of moral subjectivism.
There seems to be a widespread impression that the metaethics sequence was not very successful as an explanation of Eliezer Yudkowsky's views. It even says so on the wiki. And frankly, I'm puzzled by this... hence the "apparently" in this post's title. When I read the metaethics sequence, it seemed to make perfect sense to me. I can think of a couple things that may have made me different from the average OB/LW reader in this regard: