This new release follows the launch of Windows 10 build 14393.187 for PCs in the Production update ring. This new Windows 10 Mobile preview release likely means Microsoft is close to launching this update for all Windows 10 Mobile phones in the near future.
Microsoft’s support page has what’s included in this update:
Improved reliability of Windows Shell, map apps, Internet Explorer 11, and Microsoft Edge.
Addressed issue causing push-button reset to not work correctly and roll back on devices with language set to any of the Unicode languages.
Addressed issue causing devices to crash after disconnecting an e-reader that was attached to the device.
Addressed issue causing devices to not recognize a Secure Digital (SD) card if it is inserted and removed multiple times.
Addressed issue causing some apps to not respond to the commands in the app bar in Windows 10 Mobile.
Addressed issue that sometimes blocks alarm notifications in Windows 10 Mobile.
Improved support for using the camera app in Windows 10 Mobile Enterprise.
Addressed additional issues with rendering 4K resolution, missing Start menu tiles when running on battery, Internet Explorer 11, Microsoft Edge, Bluetooth compatibility, graphics, display rotation, app compatibility, Wi-Fi, Feedback Hub, Miracast, Windows Shell, revised daylight saving time, and USB.
Security updates to Microsoft Edge, Internet Explorer 11, Microsoft Graphics Component, Windows kernel, and Adobe Flash Player.
Thanks to everyone for the tips!