>>54598463The general assumption is that the powers that be assumed the anime would still be running until like gen 20, which is why delaying Ash's league win another gen or two means they could also delay him challenging the Elite Four because they wanted to make him steadily improve over time.
Of course it all went to shit after that, with the gen 7 anime being a Yokai Watch-inspired fuckfest where they had Ash win a meme "league" and screeched that up as if it actually meant something, and when nobody cared, then went max damage control and had him become world fucking champion in gen 8 before tossing him aside and rebooting the entire anime with a new protag.
It was stupid and terrible but it sort of made sense at the time.