The “problem” seems based on several assumptions:
that there is objectively best state of the world, to which a Friendly should steer the universe
pulling the plug on a Virtual Universe containing persons is wrong
there is something special about “persons,” and we should try to keep them in the universe and/or make more of them
I’m not sure any of these are true. Regarding 3, even if there is an X that is special, and that we should keep in the universe, I’m not sure “persons” is it. Maybe it is simpler: “pleasure-feeling-stuff” or “happiness-feeling-stuff.” Even if there is a best state of the universe, I’m not sure that are any persons in it, at all. Or perhaps only one.
In other words, our ethical views, (to the extent that godlike minds can sustain any) might find that “persons” are coincidental containers for ethically-relevant-stuff, and not the ethically-relevant-stuff itself.
The notion that we should try to maximize the number of people in the world, perhaps in order to maximize the amount of happiness in the world, has always struck me as taken the Darwinian carrot-on-the-stick one step too far.
Note that there’s a similar problem in the free will debate:
Incompatilist: “Well, if a godlike being can fix the entire life story of the universe, including your own life story, just by setting the rules of physics, and the initial conditions, then you can’t have free will.”
Compatibilist: “But in order to do that, the godlike being would have to model the people in the universe so well, that the models are people themselves. So there will still be un-modeled people living in a spontaneous way that wasn’t designed by the godlike being. (And if you say that the godlike being models the models, too, the same problem arises in another iteration; you can’t win that race, incompatibilist; it’s turtles all the way down.”)
Incompatibilist: I’m not sure that’s true. Maybe you can have models of human behavior that don’t themselves result in people. But even if that’s true, people don’t create themselves from scratch. Their entire life stories are fixed by their environment and heredity, so to speak. You may have eliminated the rhetorical device used to make my point; but the point itself remains true.
At which point, the two parties should decide what “free will” even means.