Faculty may see quiz attempts and discussion posts from students who dropped, or were dropped from the course.
See the following link with instructions on how to view withdrawn students from the D2L Classlist: https://kb.ccconline.org/article.php?id=23
If a student takes an assessment or participates in a discussion, then drops the course, faculty see that there were attempts on the quiz list screen. Yet, when faculty open the quiz it says there were no attempts. Similarly, faculty and remaining students will see discussion posts from students that dropped. The dropped student will not appear in the gradebook though.