I monitor my son playing this everytime. Have maximum child protection policy turned on for the game, and do not let him use a headset.
He can't friend anyone. Decline all requests, only play games you can't chat in like writing on a sign, and he knows if he tries to talk to anyone on it he gets perma banned from it.
Has worked so far!
It's hard … parenting. It's like you have to give a shit.