Bit more than "here and there." Underestimating the amount of players that don't play for their community program. All levels, boys and girls.
In your own town of Farmington, 3 years ago there was 3 neighbors/houses in a row with kids playing hockey for Lakeville North (Peewee), kid at Lakeville South (Bantam) and a kid at Edina (Peewee.) Yes, lived in Farmington, kid played for Edina in Peewees.
It's not a lack of kids playing growing up, that's still a healthy number, it's where they play. And it's not solely because people with kids that play hockey all move(d) to the same town(s). They don't have to move.
Also underestimating when all the best players leave their home association, that once you get to the HS level, kids stop playing hockey for the sake of playing hockey. They don't want to lose 10-0 every game, they don't want to have a 0% chance of playing in The Tourney, or even a 0% of even sniffing a section final. That's where those kids stop playing because: "if I was good enough I wouldn't be playing in my own town, I'd be playing for [same teams that make tourney year after year.]"
Bigger issue in girls hockey than boys, I'd say. But much more of an issue than it happens "here and there." Closer to on-par with "demographics change" and "people move."