Dragon Ball Super exists in a weird place in the Dragon Ball canon. The more it develops, the more pieces it's going to have to set in place for the "End of Z" years after the events of this series. Dragon Ball Super has already introduced new elements such as Gods and the multiverse into the canon, and the way recent developments are looking in the latest chapter of the manga, it might just be shaking up the canon in a much more unexpected way.
In Chapter 49 of the series, it's revealed that Majin Buu had God ki all along. But when he was separated into the good and evil versions, that God ki was lost. But the lingering question is whether or not Kid Buu's destruction resulted in the full loss of that power. So, is Dragon Ball Super setting up Uub's introduction to the series much earlier than he's supposed to be?
As a brief refresher, Uub is the reincarnated form of Kid Buu who appeared years after the Majin Buu saga. Taking part in the tournament at the end of Dragon Ball Z, Goku decides to train Uub due to his latent Buu powers as a way to finally get the rematch with Kid Buu that he wished for when Kid Buu was destroyed by the Spirit Bomb. Chapter 49 actually features a prominent flashback to Kid Buu's destruction, and that could get the ball rolling to bring in Uub.
The Grand Supreme Kai, currently fighting Moro, can't access the full swath of his abilities due to the loss of God ki from the Majin Buu separation. With the flashback to Kid Buu, there's an implication that the reincarnated Uub has inherited that God ki. Grand Supreme Kai lamenting his "obliterated" power only further raises an interesting bit of foreshadowing. It could be a total fake out as Grand Supreme Kai has no idea that Buu's been reincarnated.
It's already been established that Uub is in the world of Dragon Ball Super, so it wouldn't be a major leap to mention him in a future chapter either. This current Moro arc has been utilizing many of the lingering threads from Dragon Ball Z such as New Namek, Buu's separation, and the Grand Supreme Kai Buu once absorbed thousands of years ago, so it wouldn't be too wild of an idea to capitalize on the Uub thread too.
While this would be a major retcon for the series, giving Majin Buu God ki (or saying that he had it all along in secret, rather) is a retcon already. So the door's wide open. As for what Uub could bring to the series if introduced earlier, there's a whole potential story of Goku's training of him. And with Gogeta and Broly brought into the official canon, elements from Dragon Ball GT such as "Majuub" are on the table too.
Uub totally could or could not be set up for an appearance in a future chapter of the series, but it would open up a new world of possibilities if he did arrive. Just imagine how cool it'd be if Goku starting training an Uub who could use God ki?
What do you think? Do you think Uub could be coming in a later chapter? Let us know in the comments! Dragon Ball Super currently airs its English dub on Adult Swim during the Toonami programming block on Saturday evenings. It is also available to stream on Funimation and Amazon Video. The Japanese-language release of the series is complete, and available to stream on FunimationNOW and Crunchyroll. The manga has chapters that can currently be read for free thanks to Viz Media, and Dragon Ball Super's big movie, Dragon Ball Super: Broly, is now available on Blu-ray and DVD.