Microsoft: Old Windows updates now expire to improve speed, security
Microsoft says it regularly evaluates Windows updates for expiration to make the entire update process faster and safer by removing older releases that have already been superseded by newer packages.
Installing updates is slower and their size gets incrementally bigger due to the long backlog caused by the two or more updates for each Windows platform released every month.
Also, older packages are delivered via Windows Update as part of cumulative updates, further decreasing update performance and making the entire process take longer than needed.
Microsoft increases Windows Update's overall performance by marking earlier updates for expiration as part of a regular evaluation process.
"Microsoft produces two to three updates per supported Windows platform monthly. Many of these updates, however, are cumulative and include all earlier updates that have been published for that platform," said Christine Ahonen, a Program Manager at Microsoft.
"By expiring older, redundant packages, you get better performance, shorter scan times, a faster user experience, and reduced risk of deploying older updates which have been superseded with newer, more secure ones."
https://www.bleepingcomputer.com/news/microsoft/microsoft-old-windows-updates-now-expire-to-improve-speed-security/