iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple Modifies Software Update for Windows
The practice received some criticism since the "update" appeared for individuals who had never installed a previous version of Safari. Apple has reportedly revamped their Software Update to clearly distinguish "New Software" from "Updates":
Image from Asa Dotzler
Safari now occupies a place in the "New Software" box, but continues to be offered to all Windows iTunes users. Even still, Mozilla's Asa Dotzler believes Apple should not leave the software checked by default.