Windows 10 Mobile update sent out to non-Insider Lumia 950 and Lumia 950 XL models

Included in the update to Windows 10 Mobile 10586.29:
You will see additional improvements in upgrade experience, including devices with limited free space, map rendering on update, and RCS enabled device settings.
Improved application backwards compatibility for Windows Phone 8.1 Silverlight applications.
Edge performance and stability has been improved. Auto-completion has been updated to allow user to more easily edit the end of the URL in the address bar.
Additional Bluetooth stability improvements.
We have resolve issues on switching the active cellular connectivity profile on Dual SIM devices"-Microsoft
You will see additional improvements in upgrade experience, including devices with limited free space, map rendering on update, and RCS enabled device settings.
Improved application backwards compatibility for Windows Phone 8.1 Silverlight applications.
Edge performance and stability has been improved. Auto-completion has been updated to allow user to more easily edit the end of the URL in the address bar.
Additional Bluetooth stability improvements.
We have resolve issues on switching the active cellular connectivity profile on Dual SIM devices"-Microsoft
Another thought that comes from today's update, is that Microsoft chose AT&T to carry the Microsoft Lumia 950 because it knew that the nation's second largest carrier might be more liberal when it comes to the Windows 10 Mobile software update testing process. Other major U.S. carriers, especially T-Mobile, complained that it wanted to offer the Lumia 950 and Lumia 950 XL to customers, but never got the opportunity from Microsoft. At the time, it was believed that Microsoft was looking to downplay the new handsets so that it could focus on a new Surface Phone. While the latter reportedly will launch late next year, it is possible that other stateside carriers weren't interested in allowing Windows 10 Mobile updates to be downloaded without getting the last word on timing.
source: WindowsCentral