Deferral options are still available in the Group Policy. Tap on the Windows-key, type gpedit.msc, and hit the Enter-key to launch the Group Policy Editor (professional versions only).
Go to Computer Configuration > Administrative Templates > Windows Components > Windows Update > Windows Update for Business.
There you find "Select when Preview Builds and Feature Updates are received" and "Select when Quality Updates are received".
https://www.ghacks.net/2019/05/28/windows-10-1903-the-case-of-the-missing-update-deferral-options/
Go to Computer Configuration > Administrative Templates > Windows Components > Windows Update > Windows Update for Business.
There you find "Select when Preview Builds and Feature Updates are received" and "Select when Quality Updates are received".
https://www.ghacks.net/2019/05/28/windows-10-1903-the-case-of-the-missing-update-deferral-options/