If a boy (9) has been doing this, one child discloses to parent, parent reports it, school interviews a whole list of girls (yours among them), finds it has been happening to your girl over a sustained period, speaks with your girl about it, gives the group of girls a counselling session at break time....
Would you expect to be informed, as a parent?
Or would you expect to be sent on your jolly way for a lovely Christams break, and have a tearful DD9 tell you this evening about the investigation and counselling that took place at school all week?