UPDATE: it seems I was a bit too quick with my analysis. Thanks to reader and commenter Shane for pointing this out! I had checked our internal documentation with manually imported updates and couldn’t find KB2775511, so I had drawn the premature and incorrect conclusion Microsoft had withdrawn the update from the WSUS channel. After Shane’s comment I deep-dived a bit more and yes, it seems the update was probably never available through WSUS, so it seems someone has imported these updates in our environment without editing the documentation. Bottom line: everything is normal, except for the state of our internal documentation 
Today I’ve noticed the KB2775511 updates were missing in recently set up WSUS servers, while they were effectively provided on older WSUS servers:
On an older WSUS server
On a newer WSUS server
KB2775511 contains these 4 updates:
- Update for Windows 7 (KB2775511)
- Update for Windows 7 for x64-based Systems (KB2775511)
- Update for Windows Server 2008 R2 for Itanium-based Systems (KB2775511)
- Update for Windows Server 2008 R2 x64 Edition (KB2775511)
All other Windows 7 and WS08R2 non-expired updates were still offered on the newly established WSUS servers.
While it seems KB2775511 has been revoked for the WSUS release channel & update source (no idea why Microsoft has done this though), it’s still available through the Microsoft Update Catalog:
