Windows 10 Build 16251.1000 is the first 'Redstone 4' release

Yesterday, Microsoft released the first build for next major Windows 10 update, codenamed Redstone 4. At the same time, Microsoft also released a build for Fall Creators Update.

Interestingly, both releases are using the same build number, 16251, different on the minor version. While the RS4 build is 16251.1000, the Fall Creators Update build is 16251.0

Therefore, we can guess there are minor changes between both builds. In my opinion, it's all about merging code. For example, Microsoft has been working on a feature called Timeline which was expected to be released within Fall Creators Update, but was delayed. So, the code already produced could be available on this first Redstone 4 build. In other words, this and the next few builds for Redstone 4 could just be the Fall Creators Update code merged with other unfinished code, so that Microsoft can keep working on the next features. At the end, from the perspective of Windows Insiders, they are just equal because the same features are available. However, this is not officially confirmed, is just my guess.

In case you are interested in ISOs for build 16251.1000 (Redstone 4), I won't upload them. Instead, I uploaded ISOs for the Fall Creators Update and you can find them here.