To spell out some of the complications -- does the genie only respond to verbal commands? What if the human is temporarily angry at someone and an internal part of their brain wishes them harm. The genie needs to know not to act on this. So it must have some kind of requirement for reflective equilibrium.

Suppose the human is duped into pursuing some unwise course of action? The genie needs to reject their new wishes. But the human should still be able to have their morality evolve over time.

So you still need a complete CV Extrapolator. But maybe that's what you had in mind be pointing at the wishes of a particular human?