DB Disruption: What if Goku Black invaded DragonBall GT?

Amidst escaping from the future, Goku Black spotted Trunks in his time machine. Shooting a laser only a little earlier than in the official story, his energy barely hits the machine before it disappears into the void of time. Damaging some of the controls, the time machine does not go to it's predetermined destination, but jumps to an alternate timeline; A timeline depicted in a show called Dragon Ball GT.
After the defeat of the Shadow-Dragons, Goku says goodbye to all his friends and family and leaves with Shenron. Later that night while Vegeta and Bulma are celebrating their recent victory, they hear a loud explosion outside Capsule Corps. There stood the iconic time machine covered in rubble and smoke. Up above, a dark-purple portal opens up, signaling the arrival of Goku Black.