Government arguably should be an expedient (this is Thoreau's argument anyway), and it's possible A.I. could be at least a more consistent expedient that also commits to ratting itself out anytime its ethical programming is substantially altered. That isn't at all how humans behave, they can't be programmed this way.
Merely having A.I. that concisely points out the competing ethical positions on an issue, would be an improvement to word salad propaganda; propaganda is a significant impediment to both ethical and critical thinking, so an A.I. that were to score statements on a propaganda scale would itself be useful.