Microsoft is now rolling out a tiny cumulative update for all Insiders on 14986. You should see this: Cumulative Update for Windows 10 version Next for x64-/x86-based systems (14986) (KB3206309). Apparently it just brings minor bug fixes and improvements, although Don Sarkar(Oui, you read that correctly lul) still hasn’t mentioned anything about it on her twitter account, but we’ll see if there’s anything else. In the meantime if you don’t see the update, here are the offline installers for both 32-bit and 64-bit editions.
Edit, 6:35 p.m. GMT +5:30, 20/12/2016: So it seems that the new update enables this weird setup for the brightness slider. It now features 5 modes: Darkest, Darker, Suggested, Brighter and Brightest. If it is location based, spot on Microsoft! Here’s a few screenshots, because my laptop doesn’t support Game bar lul.