Windows 10 version 1709 "Fall Creators Update" is the upcoming feature update for the stable branch of Windows 10. Also known by its code name Redstone 3, it is expected to be released in a couple of months. It looks like Lenovo accidentally leaked its release date.
The press release for Miix 520, a two-in-one tablet with support for "far-field, standby Cortana recognition", points that this feature “requires Windows 10 Fall Creators Update which will automatically update starting October 17, 2017”. A 2D/3D WorldView camera included in the tablet also requires the Windows 10 Fall Creators Update, noted in the press release, again with the mention of the October 17, 2017 date.
There is no official confirmation from Microsoft for this date. However, Asus, Dell, and Lenovo will release their mixed-reality hardware in October, which require Windows 10 Fall Creators Update. From other hand, Windows 10 Fall Creators Update identifies itself as "version 1709", which makes expecting the release in September.
Microsoft will release the Windows 10 Fall Creators Update to Insiders a week or two before the official roll out to consumers.