After releasing Windows 10 for PCs Insider Preview build 14267 to the Fast ring earlier this week, Microsoft released a build of the same number to the Fast ring for Windows 10 Mobile as well.
Build 14267 is the first Redstone release for Windows 10 Mobile. There have been six Redstone builds released for Windows 10 for PCs which date back to December. Since Windows 10 Mobile continued to roll out cumulative updates for the Threshold 2 RTM build, 10586, many were beginning to wonder when Redstone would come to Windows 10 Mobile.
As Microsoft had promised, the only devices eligible for this build are the Xiaomi Mi4, Microsoft Lumia 550, 950, and 950 XL. In the blog post, Gabe Aul notes that they have changed the criteria for Fast Ring builds, so we are likely to see them more often.
He also reminds us of the Release Preview ring, which they announced alongside Windows 10 Mobile build 10586.107. This is for those that still want early access to the cumulative updates to build 10586. If you don't want the bugs that are going to come with Redstone, the Release Preview ring is for you.
Redstone is slated to be the next major update to Windows 10, likely coming in two waves, the first wave coming this Summer.