Not a lot of folks did. The only way to know is if you happen to plug your iPhone into your computer while iTunes is running, or if you follow Apple-related tech sites daily.
I don’t know why, but Apple wasn’t very forthcoming about the nature of this update. Unlike with the “original” iOS 10.1.1, there were no release notes accompanying the re-release, at least none that I’ve been made aware of. The difference in build numbers (14B150 for the new one vs. 14B100 for the old one) suggests at least some changes were made, as users noted in the comments.
Until further notice, the true nature of this update remains esconced within the Cupertino cone of silence.