Does the principal know anything about DYS? Or is this just a fearful, knee-jerk reaction?
The advocate is just that: an advocate for your child's best interests. S/He's a neutral voice to support you and your child. S/He's someone NOT paid for by you, yet who is standing up for your child to say, "Hey, this kid has special needs. No, really, you can't blow this off."
Your advocate won't tell the principal how to manage the school any more than you are. It's about getting your child served, period.