Since Eliezer-Good is roughly synonymous to CEV, maybe we can just call it CEV from now on?

This leaves out the "rigid designator" bit that people are discussing up-thread. Your formulation invites the response, "So, if our CEV were different, then different things would be good?" Eliezer wants the answer to this to be "No."

Perhaps we can say that "Eliezer-Good" is roughly synonymous to "Our CEV as it actually is in this, the actual, world as this world is right now."

Thus, if our CEV were different, we would be in a different possible world, and so our CEV in that world would not determine what is good. Even in that different, non-actual, possible world, what is good would be determined by what our actual CEV says is good in this, the actual, world.