I always want to fix and update my quizzes when I import them. Obviously, if I'm copying a quiz from last year, I'm not going to be able to update it in the old course because it's locked. That means you need to unpublish it as soon as you import it, or else some kid is going to click on it and get the wrong version. It always takes a minute or two for quizzes to load in the new course, so I have to sit on the page and refresh it in order to catch the quiz to unpublish it.