If you've ever bought an Xbox One console bundle, you've surely found that there are some codes in the box that you have to redeem to your account for the bundled games. Prior to this method, consoles used to come with physical media, which used to make it a lot easier to sell the bundled game when the user was done with it. Now, you're not going to be able to sell it at all.
Microsoft is introducing Digital Direct, so instead of having to redeem those pesky codes, you'll be able to claim the games right at setup. Of course, you don't have to claim it, as there's an option to decide later. You can then choose to redeem it in Settings -> Account -> Included with this Xbox, or you can claim it through My Library. Once you do redeem it, it's tied to your Microsoft account.
Microsoft says that, "All included digital content will be attached to the first Microsoft Account that redeems it." Presumably, this means that if you choose not to redeem the code, you would still be able to sell the console to someone and they'd be able to, or you could even have a friend sign into the new console to transfer it.
The new feature was first spotted by some folks on Reddit that bought the new Cyberpunk 2077 bundle. The game itself isn't out yet, but users are able to add it to their account when it's available.