This change is noted in Canvas Deploy Notes (2021-01-06)
If a quiz has never been assigned to a student, and the availability dates are in the future, moderating the quiz will give the student access to the quiz.
Students should not appear on the moderate page if the quiz is not assigned to them.
Students should not be able to take quizzes that have never been assigned to them.
A published course with two sections and a student enrolled in only one of the sections
Create a graded quiz with a time limit and availability dates in the future, assign it only to the section that doesn't include the student's enrollment, save and publish
Moderate the quiz and give the student extra time
Act as the student, notice they can take the quiz, and that it appears on the quizzes index and assignments index pages