Fraser Speirs, writing for MacStories:
Two things are happening with iOS 9.3. Firstly, it brings important user-facing features, such as Night Shift, in a point release. Secondly, it brings a beta of major features for education. It is important to remember that the education features will still be in beta after 9.3 is released. I was informed by Apple that the long lead-time is intended to give schools time to thoroughly test and provide feedback on these features before the start of the 2016-17 school year in August/September.
Fraser goes in depth on all of the education features, but this is the first time I’ve heard that they would still be in beta after 9.3 is released.