It’s not surprising. If you read the behind the scenes interview sections at the back of volumes of the Super manga, it’s obvious that Akira Toriyama (or as Toyotarou calls him in these sections, “Toriyama-sensei”) saw Toyotarou as a successor and had a lot of faith in him. It would make sense that he would continue with the torch he was given. Combined with the fact that the manga ended on a cliffhanger, (Frieza is still out there!) and Toriyama-sensei was still helping out with new Dragon Ball material at the time of death, I don’t doubt that he had plans that have yet to be finished.

That said, once those plans have been caught up with and the story is wrapped in a nice bow, I think they should leave it alone. We’ve seen what Dragon Ball looks like without his influence, and I would prefer the series went out with dignity rather than become a zombie.