This is the thing you're going to write an article was a major change. It isn't even the same story anymore. Rands character from the books would never do the things he's been doing.

I am pretty sure they said that diama is a different time line than super. I gotta ask because it feels like this article was written by someone who's only seen super. Didn't do any real research deeper than scratching the surface in the hopes people would clock a fancy title.

The real answer to the article is, it's a different timeline. Diama, dream. It's explained or at least heavily implied when you get to see the time rings, that there is multiple timelines with one "main" timeline. Diama is a branch off of the main timeline, along with heros, and GT. So the reason it wasn't in super, is because it never happened. Goten and trunks are the same ages in the beginning of super and diama.