If I were doing it, I'd save computing power by only simulating the people who would program the AI. I don't think I'm going to do that, so it doesn't apply to me. Eliezer doesn't accept the Doomsday Argument, or at least uses a decision theory that makes it irrelevant, so it wouldn't apply to him.
Well, for a start, I don't think that the builders would want to be the only people in their world. And recall that this only serves to produce new humans, because simply making all existing humans immortal solves the DA as well. I think it would be more efficient to fully populate the simulation.
What is this decision theory? I haven't read the Sequences yet, sorry.
A self-modifying AI is built to serve humanity. The builders know, of course, that this is much riskier than it seems, because its success would render their own observations extremely rare. To solve the problem, they direct the AI to create billions of simulated humanities in the hope that this will serve as a Schelling point to them, and make their own universe almost certainly simulated.
Plausible?