To learn Kingdom Hearts lore going in blind you’d need an autistic kid who’s hyper-fixated on it, a couple cases of monster energy, and a weeks worth of LSD micro doses.
That should get you up to speed on about 50% of it.
Pokemon didn’t grow up with it’s player base. They try and keep the storylines Kid friendly, when I’d guess 70%+ of players are adults.
Black & White probably had the most “Adult” narratives of the series, delving into the slavery/forced labor a bit. I’d love to see the games delve into some more adult themes, but I doubt it will happen.
What needs to be remade? Nothing; I’d just like to see updated graphics, a couple tweaks in the story here and there, and maybe a few tweaks to the sphere grid.
It’s a great game, I just wouldn’t mind seeing it get upgraded a bit.