Microsoft has raised the safeguard hold put in place to block Symantec or Norton antivirus users from updating their Windows 7 and Windows Server 2008 R2 devices. The update block added on August 14 was caused by Windows updates code signed using SHA-2 certificates being deleted during installation. Microsoft has also started testing its throttled update delivery system this week with the Windows 10 19H2 Build 18363 release rolling out to a small subset of Windows Insiders in the Release Preview Ring. The soft block was removed on August 27th, 2019.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-lifts-update-block-on-windows-7-with-symantec-av/