Microsoft has released the RTM build of Windows 10 Fall Creators Update to OEMs. Windows 10 build 16299.15 is the RTM build of the Fall Creators Update, which means this is the build Microsoft will be releasing to regular users once the update starts rolling out on the 17th of October.
Build 16299.15 is also the last build of the Windows 10 Fall Creators Update that the company that Windows Insiders will get. The build is already available to Windows Insiders in the Fast Ring. Microsoft will release patches for the build to Windows Insiders in the weeks before the rollout of the Fall Creators Update starts, however. Additionally, the company will likely also release a cumulative update for the Fall Creators Update on the day of its public release with all these patches.
Windows 10 Fall creators Update is arguably one of the smallest updates to Windows 10 ever released. The update is also quite buggy in some places at the moment, which is also very concerning. But keep in mind that Microsoft will roll the update out in different phases to Windows 10 users, so most of the bugs will likely get ironed out before the update reaches all devices.