Vested interests
OTOH, Bezos' wife definitely has a BIG interest in maintaining and (if possible) improving her husband's reputation. So the fate of the book would not be one of her concerns. Indeed, if she could prevent anyone from buying it, she would no doubt be content.
I suppose it would be unconscionable to rule out reviews by close family members - but I wouldn't expect Mrs Bezos' review to be objective. (Anyone who has been married, or in a similar relationship, is keenly aware that objectivity about your nearest and dearest is not one of the greatest assets you can contribute).