In You Provably Can't Trust Yourself, Eliezer tried to figured out why his audience didn't understand his meta-ethics sequence even after they had followed him through philosophy of language and quantum physics. Meta-ethics is my specialty, and I can't figure out what Eliezer's meta-ethical position is. And at least at this point, professionals like Robin Hanson and Toby Ord couldn't figure it out, either.
Part of the problem is that because Eliezer has gotten little value from professional philosophy, he writes about morality in a highly idiosyncratic way, using terms that would require reading hundreds of posts to understand. I might understand Eliezer's meta-ethics better if he would just cough up his positions on standard meta-ethical debates like cognitivism, motivation, the sources of normativity, moral epistemology, and so on. Nick Beckstead recently told me he thinks Eliezer's meta-ethical views are similar to those of Michael Smith, but I'm not seeing it.
If you think you can help me (and others) understand Eliezer's meta-ethical theory, please leave a comment!
Update: This comment by Richard Chappell made sense of Eliezer's meta-ethics for me.
Persons have a right not to be killed; persons who have waived or forfeited that right, and non-persons, are still entities which should not be destroyed absent adequate reason. Preferences come in with the "waived" bit, and the "adequate reason" bit, but even if nobody had any preferences (...somehow...) then it would still be wrong to kill people who retain their right not to be killed (this being the default, assuming the lack of preferences doesn't paradoxically motivate anyone to waive their rights), and still be wrong to kill waived-rights or forfeited-rights persons, or non-persons, without adequate reason. I'm prepared to summarize that as "Killing: generally wrong".
What you say seems contrived to me. You could have uttered the exact opposite and it wouldn't change anything about the nature of reality as a whole but solely the substructure that is Alicorn.