I'm going to bring this up but want to say it as best I can to not offend anybody.
There are some parents that are way over bearing on their kids and do disrupt a players thinking in between games.
it does happen. And while it may not be as prevalent that it happens to every player it can happen to players enough that it can affect what happens when they come back to the field to play.
Recognize that some people are seeing this as a control issue of the coach controlling the players.
In a way it is, by controlling the environment the players are in while they are supposed to be focusing on what the team needs to do that day. Trying to keep that Dynamic intact. Team unity.
I see the problem this coach is trying to manage, but I believe that children have the right to talk with their parents about certain problems when they don't feel safe discussing them with anybody else. Not comfortable cutting off this safety net entirely.
For example, my daughter (now age 22) bluntly responded when I asked her about this, "What if a girl has her first period? Is she supposed to confide in Coach Bruce for advice on this?"
I also recall a time when DD was 14 on a fairly new team when she got clobbered verbally by two teammates in a post-game players-only meeting and was pretty distraught about it, wanted to go home. I calmed her down, and she bounced back.
A coach can encourage players to solve problems in-house, and encourage parents to let the children solve problems in-house, and I get that, but in the end, I have a tough time telling a child that she doesn't have ultimate authority in deciding how to manage her anxieties and personal issues between games.