There in an interesting explaination as to why there is a regular beta drought at around this time of year offered here: Re: iOS 9 beta 6. The meat of which is:For June and July, Apple develops their next major release via two forks- the beta fork and the secret fork. The secret fork includes support for the unreleased hardware. The last few secrets have been Siri for iOS 5, 4 support for iOS 6, Touch ID support for iOS 7, and large screen support for iOS 8. Now come August, Apple must begin the work of integrating the secret fork into the beta fork to create one release build. From the start of the integration until the iPhone September event, Apple is unable to release betas without disclosing secrets. For that reason, there are never any betas during that time. This takes about a month- 34 days for iOS 5, 37 days for iOS 6, 26 days for iOS 7, and 36 days for iOS