iOS 9 beta users can no longer review apps
This is a much needed change that will prevent developers from having their App Store ratings and reviews affected by beta-related problems that are out of their control.
Not that it applies anymore but it should go without saying that if you’re running pre-release software in any capacity you should expect bugs, don’t be surprised when something doesn’t work quite right with your favourite app, and certainly don’t go to the App Store and review said app based on that experience.