Polygon wrote a excellent article tracking the last six months leading up to The Game Awards 2018. Here's some excerpts but the whole article is worth a read.
https://www.polygon.com/features/2018/12/11/18135085/the-making-of-the-game-awards-2018
Keighley picks up his phone in his car. He's driving from Los Angeles, where he lives, to Blizzard's headquarters in Irvine. All things considered, it's a pretty short trip for him — about an hour drive, if traffic is good. But it's one of the first of many that'll take him all over the world, meeting with developers and publishers to talk about possible announcements and trailers to debut at the annual award show.
The next couple of months will be more of the same, Keighley says. He's traveling, meeting with people, and starting to get an idea for what The Game Awards will be like in 2018. When he talks, he sounds excited, almost like he can't stop himself. He also yawns quite a bit. There's a lot of work to be done, and the self-described "control freak" puts a lot of it onto his own shoulders.
The Game Awards, in August, is in a bit of conceptual phase; the team's coming up with big, high-concept ideas without knowing what's possible yet. It's a time to shoot for the stars, Keighley says, to just imagine things. Inevitably, all their pie in the sky ideas won't make it into the show, but now's not the time to worry about that. This is, as Keighley puts it, the creative phase of the show.
"And that's really sort of part of the fun of just kind of kicking things off early," he says.
That's not to say, though, that the show starts from scratch every year. As Keighley tells it, The Game Awards is an iterative process. If something doesn't work or doesn't make it into a previous show for one reason or another, the idea isn't immediately thrown out. If anything, it becomes a bullet point for the next year.
https://www.polygon.com/features/2018/12/11/18135085/the-making-of-the-game-awards-2018