>>57815596No, that was just Shudo had in mind but never told anyone else. The episode that actually set up that conflict was the Diglett episode according to his site.
He briefly considering turning his finale idea into the plot for Movie 4 but realized that it'd have to basically end the show or drastically alter its status quo going forward if it was made. He was in extremely poor health in 2000 anyway, so he entrusted Sonoda with the movies, wrote a bunch of filler scripts, pushed for Misty to leave and wrote the basic synopsis for AG before leaving in early 2001.