The main question was whether or not he had Mystic at all, returning to the even earlier questioning of whether or not Mystic was a transformation or a permanent upgrade to Gohan and his body, with some then complaining because they believe in it being a transformation and assuming that Gohan then didn't have access to it anymore.
Well given that Old Kai told Gohan to access it like he would SSJ, I don't see how it's not a transformation. And if he was unsure if he could access his SSJ form, how was he gonna access a more powerful form?
In terms of the Goten and Trunks issues, you can talk about a lack of combat experience for days, but the only way to fix that is to actually give them some training and combat experience. Otherwise, you've got two characters with massive amounts of potential (Goten, youngest Super Saiyan ever, from a powerful bloodline, and Trunks, also from a powerful bloodline, with a Future form that has proven to be right there with Goku and Vegeta in terms of strength) that is being squandered because other characters have more experience. That's silly and makes no sense. Notably, it's also the exact opposite of what was being done with Gohan back at their age.
I'll just blame their overprotective mothers. Chi-chi in particular.