I have no problem with this passage. But it does not seem obviously impossible to create a device that stimulates that-which-feels-rightness proportionally to (its estimate of) the clippiness of the universe - it's just a very peculiar kind of wireheading.

As you point out, it'd be obvious, on reflection, that one's sense of rightness has changed; but that doesn't necessarily make it a different qualia, any more than having your eyes opened to the suffering of (group) changes your experience of (in)justice qua (in)justice.