The Hide and Post feature is very useful for many reasons. Most faculty I work with would prefer to show nothing to the students for quizzes and assignments until after the due date. The settings in quizzes are excellent for formative or practice quizzes, but they are not great for higher stakes assessments in my mind and in the eyes of many of my faculty. The Hide feature does exactly what they want for these types of assignments.
The biggest issues most faculty have with the post / unmute feature is that it is manual. They need to go back to the grade book to do this sometime after the due date. It would be great if there was a Post on Date feature that would post the grades at a certain point.