I found this on a cheating website, and it’s for Halo: CEA, but I got the MCC version.
Extra Credits for Halo Reach + Bonus 11th Terminal Video on Waypoint
At the end of each Terminal video, you are presented with a code comprised of 5 Forerunner symbols. Pause the videos at this point and take pictures of the codes or draw them on a piece of paper. Log in to the Halo Waypoint console app and press “X” at the main menu. You will then be presented with a series of colored circles on-screen. Press the face buttons that correspond to the color pattern from left to right (i.e. Blue-Green-Blue-Red-Yellow-Blue will translate to X A X B Y X). If this is your first time accessing this hidden section of the app, you will immediately be presented with the code entry screen. Enter the codes you copied earlier by highlighting the Forerunner symbols that correspond to the codes you logged and pressing “A”. Then confirm the code by highlighting the 3-arrow symbol and pressing “A”. For every code you enter successfully, you will 1) unlock the corresponding Terminal video for use in Waypoint, 2) earn 7,000 credits each for the first 9 terminals, from “The Pillar of Autumn” to “Keyes”; unlocking the Terminal video from “The Maw” will net you a whopping 32,000 credits. And 3) upon entering all 10 codes, you will unlock a special 11th Terminal video that can only be viewed in Waypoint. To go back to the Waypoint main menu, select “Reset Terminal” at the Secret Terminal menu. Note that whenever you do a fresh boot of Waypoint, you will still need to press “X” at the main menu and enter the color-code in order to access the Secret Terminal menu if you want to view the videos again. You will find them in the “Alpha Halo Archive” Data Set.
Would this work on Xbox One? I don’t have XB Live, nor do I play online.