Japanese manga publication V Jump has revealed that the Dragon Ball GT incarnation of Goku will be joining Dragon Ball FighterZ as part of the FighterZ Pass 2 DLC. This kid Goku will use the Power Pole and a “Reverse Kamehameha,” and one of his Meteor Attacks will be a “Super Spirit Bomb.” Most interestingly, Goku’s “Super Kamehameha” special move will reportedly transform him into a Super Saiyan 3 “when there are two or fewer overall team members remaining.” There are no visuals yet, so we’re just going off word of mouth and trusted translations at this point.
For those not in the know, in Dragon Ball GT Goku is accidentally wished into becoming a child again by the Dragon Balls. GT is not canon and has essentially been replaced by Dragon Ball Super, and GT is not remembered especially fondly. I didn’t love the series either aside from the Baby Saga, but basically everyone agrees that Super Saiyan 4 was an awesome addition to the franchise. I’d be shocked if GT Goku’s second, unrevealed Meteor Attack isn’t something that takes him to that most badass of all Saiyan transformations!