Several games have confirmed that they will come with Xbox One X support with - amongst other things - 4K resolution being a key feature. Forza Motorsport 7 is one of these games, and it will offer a downloadable patch on day one of the XBX's release.
However, it raises the question as to how big these updates will be and if they will fill up a regular Xbox One hard drive that doesn't support 4K. Well, it turns out that they won't. Only the Xbox One X will download 4K assets, which was clarified by a Microsoft rep who said the following:
"With the launch of Xbox One X, when it comes to game content our intention is to download the correct assets to the correct console. This means, regardless of the TV you are playing on, 4K assets will be downloaded to Xbox One X (if available) and the standard 1080p assets will be downloaded to an Xbox One S."
Microsoft states that it will also release better download tools for developers, so as to make it possible to only download what you actually need. One example of this is languages, as those who play in English, for example, will generally only use that one language. By only downloading the specific one you want, you could save a lot of hard drive space and make downloads faster.
"As part our developer readiness for Xbox One X, we have made available a feature which will give them significant flexibility when it comes to what gets installed on a user's console. In addition to 4K specific assets, developers have options when it comes to language specific assets as well, which depending on the title, can drastically reduce the install footprint. This ability to intelligently install the best assets for each console and language are available on all Xbox One devices, and it will be up to the developer of the game to determine the specific implementation."
Thanks, Stevivor.