Not changed exactly. Instead of the new series trying to be different from the previous ones, they are deliberately and blatantly imitating the first one. Therefore its not an re-volution, but a re-boot.This is a reboot, all the new things compared to the other regions, plus as i said before a reboot doesn't mean Kanto N0.2. It means it's starting fresh. The fact that Ash still knows Oak is redunant. Of course he knows him he's not going to foget somebody important like Oak, it's a reboot in terms he is starting a new adventure and lots of things have changed.