I'm surprised this made it to the public BETA release cycle. As it didn't arrive last week I figured it was deemed too buggy and unstable to release the public BETA channel. But obviously it was only due to Apple not having enough time to re-compile in order to get it working for the iPhone 7 and 7 Plus, hench why we got the g-compile this week which also released as public BETA.
One have to wonder what the point of having developer and public BETA's are at this point in time. I always looked at it like Microsoft's Insider Preview Fast Ring and Slow Rings. Fast Ring is meant for developers, you get delivered early builds very often so you have extra time to test and optimise your apps but you are aware that very little care goes into the builds so be aware. And Slow Ring are for eager consumers who want to test out new releases before they are publicly available, but these builds are less prone to have dealbreaking bugs as they are only pushed when a build from the Fast Ring has been deemed stable enough to reach the next ring.
Obviously Apple's BETA's are not like this because about every build no matter how buggy they are in the developer BETA still gets pushed as a public BETA.