Η Microsoft has re-released 2 Windows telemetry updates. The two updates are: KB2952664 and KB2976978 and are addressed to Windows 7 and 8.1 respectively.
Microsoft gives a rather vague description on KB's official pages and says it is going to be installed only on systems registered in the Windows Client Experience Improvement Program.
In other words, these are telemetry updates that help Microsoft collect data from systems participating in this program and installation takes place only with users' consent.
All versions of Windows 7 and Windows 8.1 get both updates through it Windows Update.
So these updates do not come as mandatory in Windows Update, and they are optional, which means you can choose not to install them.
However, it would be good to be careful as the transition from Optional to Recommended can be done at any time with the next Patch Tuesday.
image ZDNet