Depends greatly on the teacher's teaching style.
Style #1: I've been in classes that were very structured and where we were constantly moving from one thing to the next. In those classes, we didn't have much time to worry about being disciplined. We simply did as instructed and we weren't left a lot of time to structure our class time for ourselves.
Style #2: Other classes I've been in were very laid back. We were left to our own devices much of the time. From time to time the instructor would come over and correct our posture or add some other detail. When he saw we had what he had shown us down, he would show us the next portion. This is where discipline actually kicks in. When you're left by yourself, what do you do with that time? A lot of kung fu instructors will not push you like taekwondo or karate instructors will. They will let you do what you want to do. It's not that they won't help you, but they won't help you if you won't help yourself. The reasoning actually makes a lot of sense. Those who lack the discipline to do it on their own are not going to excel in the art, so there's no need to bother with those people.
So there's your answer. They're either going to keep pushing you as in Style #1, or they're going to let you do whatever you want to do as in Style #2.