It's much much much more lucrative to make a show targeted at children. The money in anime is the merch. They can make infinite plushies, blankets, sippie cups , backpacks and toys based on the kid Goku project.
They'd be crazy if the banked on stingy 30 and 40yr olds for revenue. The sweet spot for money making is the Pokemon demographic
This is clearly what they are doing. I don't know why people don't understand they are not going to leave that children demo hanging. The Merchandising alone from this show will be crazy (Toys, trading cards, clothing etc). As you said, Pokemon is still printing money and it dropped around "GT". As someone who watched the show since the 1980's. It was targeted to children from beginning. "Z" had a more teen feel to it but even that was still targeted towards the youth. "GT" clearly had amore kid feel to it.
The issue is now we are grown a$$ Dragon Ball Fans, lol. So for some seeing Goku as a Kid again feels like a let down. It's not for me though because I'm an OG DB Fan. Kid Goku is the original. For a Franchise to continue to grow, you must be able to attract different generations. But yes, this show is targeted towards the youth. It's basically a mixture of OG DB and GT. Also they always "KId Size" Characters in franchises. Muppet Babies, Flintstone Kids, Tom & Jerry Kids, A Pup named Scooby Doo etc, you get the picture. The Trailer did bring me back to this: