Although it's not listed on their support page as of yet, AT&T has now released their June software update for BlackBerry KEYone owners who purchased their device from the carrier. The update is coming through as ABX992 and features all the security patches for June.
If you haven't already got the update downloaded and installed, go ahead and check for updates and you should find it waiting for you. As far as we can tell, some built-in apps have been updated over the previous AT&T builds but that's largely it aside from the security patches.
You can hit up the CrackBerry Forums for a more detailed look and let us know if you spot anything outside the norm that has been improved!