>>36613884The answer is because when they did try to replace Brock, the fanbase hated it and wanted him back.
Also they were probably hesitant to do such a drastic cast change (look how butthurt mistyfags are to this day), so they might've wanted to make sure half the cast was still recognizeable in Hoenn.
Finally Shudo, stated that he found Misty to be the weakest and least independent member of the cast, so he wanted to replace her with a stronger character hence May be far more driven.
Still kind of odd he was still around for DP, but I dont mind because he's my favorite character.