There's no test for Okada to have at this point. He's the Ace and can draw, he's already made.
Shibata on the other hand still needs to prove he can draw as a challenger. My guess is he's gonna do well because it seems anyone can draw at least 7k for New Japan shows, and Shibata going for the belt is an interesting novelty that should sell a lot of tickets. But he still gotta do it to confirm he can be real option for one of the two big titles, if he doesn't deliver as a draw he's going straight to the bushes most likely.