OK, just got this optional update (KB3075853). So, I go to More Information, and find that the update is for, "...some improvements to Windows Update Client in Windows 8.1, Windows RT 8.1, or Windows Server 2012 R2." That's it. That's all the information I'm given. Thanks, Microsoft, for the scant and vague description. Very helpful. It came with our old friend KB2976978, which is an update dealing with the upgrade to Windows 10.
I suppose I'd be a tad cynical in thinking that KB3075853 is also concerned with the upgrade to Windows 10? I mean, the vagueness does raise suspicions. I'm not going to Windows 10 for several months, so don't want an update that'll facilitate this. Just wondering if anyone else knows what this update is for bar the vague "improvements"?