Parental Rebellion at School Meeting

So here's the thing, I was at my kids' school meeting a few weeks ago. My daughter, Lily, is starting high school this year and the principal was hosting an orientation session for parents to get familiar with what we can expect as they transition from middle to high school. I've always been fairly involved in school stuff since both kids were younger, but I have to admit that these big meetings are getting a bit much for me lately. Anyway, during this meeting, the principal started talking about some new rules for students regarding their cell phones, basically no devices allowed in classrooms or hallways at all. My kid is always on her phone and it's driving me crazy sometimes. I wanted to speak up and say something, but honestly, I'm tired of everyone telling my kids what to do. So when the principal asked if there were any questions from parents, I put up my hand and said something along the lines of, 'I appreciate all this information on new rules, but you know how it is with teenagers, just let them have their phones. They need them for everything!' The room fell silent; everyone was staring at me like I'd just pulled a fire alarm or something. I didn't mean to be rude, of course, I was just tired and maybe a bit overworked too. But when the principal started listing all these reasons why cell phones are problematic for students' learning, my heart sank because Lily's going to be so upset about it. After the meeting, I apologized to her later for speaking up without thinking first. Anyway, am I really that bad of a parent or is it normal for parents to feel like they need to say something when someone else is making rules about their kids? And what should I do next time instead, just nod and agree with everything or go home feeling angry?