>

A good example we should all be able to agree on is politics. Conversations start that a teacher can't help but a child shouldn't come home saying "Biden is an idiot and is ruining this country" any more than "Trump is racist" and when you ask them where they got it they say "teacher said...". 
What does that have to do with math or science? Perhaps in a history class there could be some overlap. I think we should all be able to agree that a teacher should never speak in a way that gives any definite opinion on sexuality, politics, or religion.
The excuse send to be "we weren't ready to have this discussion with the kids". Bullshit. When you have (or teach) kids, you often have to meet them where they are. If they're encountering topics of racism, you talk about it. And nine is plenty fucking old, so there's no copping out there, either. >

This might be my personal biases talking, but I think it's more likely that they were worried about the parent's reaction.
"this was not the conversation we had prepared Mrs. Robek, the students or parents would take place."
I think kids of that age should learn that racism is stupid, arbitrary and socially constructed. Not sure that everyone agrees with that. >

That's another standard excuse, but it's usually about hypothetical parents. Sure, some sometimes complain, but either schools are way more gun-shy about this than the numbers bear out or it's just a way to shift the blame for a decision that they were going to make anyway.
Most parents I know would like their kids to have these conversations at school. Ideally, also at home, but a lot of parents would be happy the school is doing it for them. It was part of of curriculum from kindergarten when I was in school.
Realistically, you read s book about the stupidity of treating people differentlywho look different >

It’s not at all hypothetical. My district in a liberal state has been receiving parent complaints since the summer about books, topics, etc. >

What books, what topics, what kinds of complaints? >

Do you really need an enumerated list?  Any topics that parents disagree with or might cause their children to become independent thinkers.  The excuse the school gives by suggesting the children are not ready for the topic when they were the ones to bring it up is laughable. >

I agree with the overall sentiment but I do need a list to make an informed decision. There are things that clearly should not be discussed with anyone but a parent. >

Is that clear though?  What would be an example of a topic that clearly only parents should discuss with children, particularly when it is the children that bring up the subject in relation to the material being covered?  I can't think of a subject that can't be discussed in an age-appropriate way.  
Public or even most private education isn't set up to provide à la carte educational services.  If you want that you have to home-school or hire a private teacher.