Windows 10 October 2018 Update Build 1809 is now ready for broad deployment, rather than targeted deployment. Microsoft announced today that they are designating the update as being in the “Semi-Annual Channel”” Microsoft had previously released the update to targeted devices in order to determine existing issues have been resolved and no new problems have appeared. Some Windows 10 users running on Windows 1803 have still not been offered the 1809 update as recently as 2 days ago. Check for new updates today or tomorrow and it should now be available.”
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-version-1809-is-now-in-broad-deployment-available-to-everyone/