Changes to Security Update Links
Updates have historically been published on both both the Microsoft Download Center and the Microsoft Update Catalog and Security Bulletins linked directly to update packages on the Microsoft Download Center. Starting May 10, some updates will no longer be available from the Microsoft Download Center.
Security bulletins will continue to link directly to the updates, but will now point to the packages on the Microsoft Update Catalog for updates not available on the Microsoft Download Center. Customers that use tools linking to the Microsoft Download Center should follow the links provided in the Security Bulletins or search directly on the Microsoft Update Catalog.
Informational in style, but this is news that could potentially break the possibility to update offline, thereby not being able to choose not to install updates which contains telemetry etc.