With today’s cumulative update Microsoft has added support to a new device. Alcatel Onetouch Fierce XL now supports Redstone Insider Builds for Mobile.
From Windows Blog:
“We are initially making new mobile builds from our Development Branch available only to devices that shipped with Windows 10 Mobile. Currently this includes the Lumia 950, 950 XL, 650, 550, and Xiaomi Mi4. Today we are also adding support for the ALCATEL ONETOUCH Fierce XL. We plan to expand to other devices once we start releasing Windows 10 Mobile to other devices”
Earlier Redstone build was only available for Lumia’s shipped with Windows 10 Mobile and Mi4. From build 14267.1004 Alcatel is also a part of Redstone Insider Build. Other devices will get the Redstone Insider Build after the General Release of Windows 10 Mobile TH2 (10586) Build.