Oda needs to hype up Awakening, because that's most likely the last power up that Luffy will get. And what's better way to do it than via the 3 most powerful DF-dependants users: Big Mom-Kid-Law.
So awakening will be the theme of the Big Mom fight, while Conqueror Coating will be the theme of Kaidou fight. 2 most powerful powerup, for 2 Yonkou. Fitting right?
Not to say that Kid will not unlock COC-coating tho. He will, but I don't think it's gonna be in Wano.