The Supreme Court ruled that parents could, indeed, opt their children out of parts of public school curricula that violated those parents’ religious belief. In Mahmoud, et al. v Taylor, et al., the Court held

the public-school system in Montgomery County, Md, had placed “an unconstitutional burden on the parents’ rights to the free exercise of their religion,” according to the majority opinion written by Justice Samuel Alito.
“A government burdens the religious exercise of parents when it requires them to submit their children to instruction that poses ‘a very real threat of undermining’ the religious beliefs and practices that the parents wish to instill[.]”

The three “liberal” Justices demurred:

Requiring schools to provide advance notice and the chance to opt out of every lesson plan or story time that might implicate a parent’s religious beliefs will impose impossible administrative burdens on schools[.]

The problem isn’t that chaotic, however:

Some parents from several religious backgrounds—Muslim, Catholic and Ukrainian Orthodox—objected to [a collection of books with LGBTQ themes and characters]. The school board said in court filings that it initially tried to accommodate opt-out requests, but doing so became “unworkably disruptive” due to “unsustainably high numbers of absent students.”

In other words, the school board was inconvenienced by not being able to dictate to parents how the school board would treat those parents’ children. Never mind that the objections were so widespread that the school board was unable to impose its will on all but a relative few. That clear cut a separation is hardly chaotic.

The chaos about which those three Justices bleated was caused by the school board and would be caused by other school boards who object to parents not meekly rolling over and kowtowing to the Know Betters of school boards more interested in their Leftist ideologies than they are in teaching the parents’ children.

These three Justices know this. They claim to worry about Court decisions deprecating respect for our court system, but it’s attitudes like those of these three that lead to that deprecation.

An aside: such chaos as might occur from enforcing parental rights, religious and otherwise, would be virtually eliminated were State and Federal governments to get out of the way of school choice, illustrated by voucher and charter schools, parochial schools, and home schooling. Parents could freely exercise their [religious beliefs] vis-à-vis the parameters of their children’s education if they had unfettered access to such a range.

The Court’s ruling can be read here.