The options for showing results to students described on the quiz options page in the Canvas Guides only apply to students who have submitted the quiz. Note that the feedback option is separate from showing the correct answer, though the incorrect answers will be indicated. That does allow for some unauthorized collaboration between students.
Another option is to send the comments to students using the Conversations tool, which is not as convenient as the auto-feedback but would make it a bit harder for students to share details with those classmates.
You might decide that the results viewing options in New Quizzes provide options that better suit your needs.
