That rule (only 3 out of towners) bit the dust around 2015-2016. All of a sudden the PPE girls teams started being >66% out of town girls, and routinely only around 5-7 in total would be at practices. My daughter got a TON out of those workout practices (couldn't do any teamwork stuff), but it was a joke. Girls would fly in to wherever that weekend's tourney was, and would play only those games together. Little cohesiveness as a unit and not much bonding as they were never together more than a few hours.
My daughter switched to D2 AA hockey and had WAY MORE fun and made much more progress than on the PPE. On PPE she was 4th line. On AA she was first line, PP, and PK and got recruited to play college hockey. So, no I don't feel like PPE does much of anything for local kids.