Abusive language at that age is a sad commentary. I do not allow abusive language even for my team at the D1 College Women level.
Good sportsmanship is a modeling behavior.
But certainly it appears one in which does need to be taught. Studies have shown that as players become elite players i.e., college or profession there is a corresponding decline in moral reasoning. And if the coach is that ignorant to display that kind of behavior he should not be coaching. As players realize yellow cards for misbehavior, so too a similar matter could be brought before the officials of the club that the coach represents. Thus it's his call.