Warning: Spoilers or Dragon Ball Super chapter 89Gohan and Dragon Ball Super's ongoing arc because their presence would contradict events as they occur in the Dragon Ball Super: Super Hero film.
In Dragon Ball Super chapter 89 by story writer Akira Toriyama and artist Toyotarou, the android Beta No. 1 touts to Goten that he's Dr. Hedo's masterwork while Trunks and Mai listen nearby. This massive namedrop greatly confuses Goten to the point where he goes out of his way to say that he's never heard of Dr. Hedo. While this might seem like an innocuous point to most, Dragon Ball fans paying close attention will notice this removes the possibility of Gohan or Piccolo appearing in the new manga arc.
Piccolo & Gohan Don't Know Who Dr. Hedo is in Super Hero
It wasn't enough that Beta No. 1 divulged Dr. Hedo's name with Goten. Goten actually repeats it, further cementing that the name didn't go over his head. Even though Mai and Trunks' proximity to the conversation implies that they heard the name too, this latest chapter of Dragon Ball Super doesn't show them reacting to it. Regardless, since Goten most assuredly knows his name, he can't come into with either Gohan or Piccolo in this story because the two of them aren't familiar with Dr. Hedo's name when they hear it in Dragon Ball Super: Super Hero, which takes place afterward. Since Dr. Hedo is a major antagonist in this manga arc, the name would have undoubtedly come up in conversation should Goten meet with either Piccolo or Gohan.
To a lesser degree, this latest chapter of Dragon Ball Super features Trunks seeing the larvae form of what's clearly Cell Max upon opening a file from Dr. Hedo's stolen disc. Even though the program plants a computer virus on the laptop Trunks is using, he still saw the image at least once and, similar to what Goten later repeating Dr. Hedo's name signifies, Trunks vocalizes that he saw "some freaky creature." Trunks would also have announced his findings to Piccolo and Gohan if they ever appeared in this manga arc, and just a basic description of it would have undoubtedly bought Cell to mind for the two heroes. But since both Gohan and Piccolo are surprised upon hearing the name "Cell Max" in Super Hero, they couldn't have been told about a larva.
Trunks & Goten's Super Hero Absence Finally Explained
These findings also simultaneously justify why Goten and Trunks don't appear for most of Super Hero until Bulma brings them as backup. If they were more involved earlier on in the film, then they would have shared everything they knew from their shenanigans in Dragon Ball Super's ongoing arc. This would have ruined a substantial amount of the story in the manga, especially the first and second chapters. In addition to Gohan and Piccolo's absence giving more time for Trunks and Goten's characters to shine, it also creates the impression that the majority of this story will have to remain an isolated incident, which could bode well for the series. Besides Cell Max's "head" weakness that Dr. Hedo's Gammas has to tell them about in Super Hero, Goten and Trunks can learn as much about Dr. Hedo as possible without the series' creators having to worry about anything they discover not aligning with Gohan and Piccolo's stories in Dragon Ball Super: Super Hero.
Dragon Ball Super chapter 89 is available on Viz.com.
