early warning of new ios releases

Hi,


We develop iOS apps for the enterprise.


When Apple release a new version of iOS then, typically, most of their user base upgrades to this new release on day one.


We would like an early warning of the release so that we can QA our apps against it to ensure there are no issues.


Does Apple provide any mechanism for getting an early warning of upcoming iOS releases so that we can test them and fix any issues before it goes out to the wild?


Thanks in advance.