Kristen already addressed this, but I want to make an additional point. As she said, the likelihood of a last place team ending up first (in a large division) is unlikely. So what they do is essentially take the top teams (top 30% or 50% or whatever) and spend tonight ranking them as to how the bids would fall out if today was the only competition day.
That way when the divisions are over tomorrow, they can pretty quickly adjust the rankings and award the bids. And if someone comes out of nowhere, it's easier to adjust to a single team instead of having to do the entire ranking.
If they didn't, they would have to do ALL worlds teams awards and bids last and everyone would be screaming about how long awards take. With no Jammy to entertain, they have to be more creative! :D
Also, it's just part of being prepared. Frankly, I'm sure that other event producers do something very similar; they just don't have as many bids to determine.