Now if a rumor has to be believed it seems Microsoft may push Build 10586.104 to Insiders next week. This is bit surprising as it seemed that Build 10586.71 may be the build going to Slow Ring and finally to everyone including Windows Phone 8.1 users. This was hinted by Gabe Aul and it was expected that Fast Rings Insiders may finally receive the first Redstone Mobile Build. But this will mean Microsoft may still wait for one or two more weeks before pushing Redstone Mobile Build to Insiders with a Lumia 550, Lumia 950 and Lumia 950 XL first.
Windows 10 Mobile build 10586.104 should be available for Insiders in the Fast ring in the coming week.
— Core Insider Program (@CoreInsiderProg) February 3, 2016