Η Microsoft will soon end support for Windows 1909 version 10, also known as “19H2” or November 2019 Update. So the Redmond company started urging users of the older version to upgrade directly to the 2004 version.
After May 11, 2021, Home, Pro, Pro Education, Pro for Workstations editions of Windows 10 version 1909 and all Windows Server editions in version 1909 will no longer receive security updates.
Microsoft has already started upgrading Windows 10 version 1909 devices to Windows 10 version 2004. By upgrading to version 2004, you should not encounter problems, as according to the company this version is considered reliable.
Interestingly, the latest version of Windows 10 now is version 20H2. In fact, all its features are present in the 2004 version with cumulative upgrades. "upgrade" installs an activation package that only activates a few new ones possibilities. It was also used for Windows 10 version 1903 and 1909, and now for versions 2004 and 20H2. However, 20H2 is not yet offered to 1909 users.
More information can be found from here.