For now, Steam will only automatically update games you’ve installed if you’ve played them in the last three days. Instead, the update will be spread out over several days. That being said, you will still have the option to manually update them at any time, should you suddenly want to play them.
Alternatively, you can schedule automatic updates on your own or self-throttle your connection to Steam. And especially for games you haven’t played in a very long time, you can turn off automatic updates altogether. These are all existing features of the platform, which Valve saw fit to remind us of. With a lot of people staying home, it’s only natural that bandwidth becomes a more limited resource than before. And in the same vein, it’s expected that more people are on Steam, playing their favourite games. So it makes sense that the company wants to preserve bandwidth for its service. After all, the digital PC games platform has broken its own concurrent user record multiple times in recent weeks. (Source: Valve)