Microsoft’s Windows Insider team has announced release of Windows 10 Mobile Creators Update to Release Preview Ring. This announcement comes on the day when Microsoft has announced official release of Windows 10 Mobile Creators Update to general public or non-insiders.

Microsoft is only supporting 13 smartphones officially for Windows 10 Creators Update. But in case your device is not supported and you want, you can remain on Creators Update by moving to Release Preview Ring.

You can read what Windows 10 Mobile Creators Update brings with itself by clicking here.

Today, we have released the Windows 10 Creators Update for Mobile (Build 15063) to the Release Preview ring.
Going forward starting with the Windows 10 Creators Update, the following Windows 10 Mobile devices will be officially supported in the Windows Insider Program going forward:
HP Elite x3
Microsoft Lumia 550
Microsoft Lumia 640/640XL
Microsoft Lumia 650
Microsoft Lumia 950/950 XL
Alcatel IDOL 4S
Alcatel OneTouch Fierce XL
SoftBank 503LV
VAIO Phone Biz
MouseComputer MADOSMA Q601
Trinity NuAns NEO
Devices not on this list will not officially receive the Windows 10 Creators Update nor will they receive any future builds from our Development Branch in the Fast and Slow rings that we release as part of the Windows Insider Program.
If you are a Windows Insider on an unsupported device, you can stay on the Windows 10 Creators Update and receive Cumulative Updates via the Release Preview ring. However, you do so at your own risk as it’s unsupported. If you are on one of these unsupported devices and in the Fast or Slow ring, you will need to switch to the Release Preview ring via Settings > Update & security > Windows Insider Program.

Source: Microsoft