We reported via our sources that Microsoft may roll out Windows 10 Mobile RTM or Public Release build to Windows Phone 8.1 devices owners starting mid-November to end of November. We also told you that the release build is the Build 10586. Even the hands on video of Windows 10 Mobile Build 10586 was leaked by folks at OneTile.
However Microsoft is expected to sign off Windows 10 Mobile Build 10586 as early as next week, but a recent reports claims that there is a bug in build 10586 and it is causing “Reboot loop” for some on doing a hard reset.
Now LumiaHelp (Official Lumia support Twitter account) has confirmed that Windows 10 Mobile will begin rolling out to Windows Phone 8.1 devices in December. But sadly they did not provide the accurate timeline of the release. (https://uniforumtz.com/)
@ImAkhil_kp 1/2 Apologies for the confusion. We expect to begin rolling out the Windows 10 Mobile update in December.
— Lumia Help (@LumiaHelp) November 5, 2015
https://twitter.com/LumiaHelp/status/662272836451495938
https://twitter.com/LumiaHelp/status/662272866289774592
However we expect this to happen very soon and Windows Insiders can receive build 10586 later this week or early next week.