1. Yes, they will definitely let you know whether or not are off from the waiting list.
2. Unfortunately, sometimes yes. The purpose of admission office is to fill the projected freshmen class and sometimes this will take more than what they expect and this task will not be easy even for schools!
我能感受到您现在的心情和苦恼。对于您的问题，简明并直接的回答是
1.学校肯定会通知您是否被录取
2.遗憾的是，招生办的老师是要招到足够的新生。有时确实是需要比预期更多的时间，这个工作对于校方也是不容易的。
