The next major windows 10 update is now released to windows insiders in fast ring. This build 17134 is referred to as the RTM build which will be released to the windows users as feature update as there are no known bugs in this build.
The previous build which was 17133 released last month was known to be the original RTM build which was planned to release as the April 2018 Update on 12th April but due to the discovery of blue screen of death error at the last minute the release was postponed to May and a newer build 17134 was released which included the fix to bug.
Currently the build is only available to download to windows insiders in the fast ring.
Update: A bug which crashes the settings app when changing the default apps was discovered by the insiders. The new bug can seriously delay the launch of the update again. Hope Microsoft will provide the users with a cumulative update soon and fix the bug.