I want some opinions about Nibiru, and planet X. L

I want some opinions about Nibiru, and planet X. Last year when our youngest was a freshman, they learned about it in science, during the astronomy section. This year, it has been taken out of the curriculum. They got new books. She has a friends that are freshman this year and it is not mentioned in the new books. Why are the kids not able to learn about it now, when they could last year? One of her friends asked about it the first week of school. The teacher told the class " There is no planet x or nibiru." and that is all she would say about it. Kind of strange when it was the same teacher that told my kid last year and showed them telescope pics! Amy theory's? We know it exists. But, what does anyone think is gonna happen?