We have seen what teaching people about this leads to, because we've been doing it for decades, and the result is not a lack of racism. You don't solve racial division with racial division.
Most of these efforts do shelter kids from history. Kids learn a false narrative that slavery was just evil white southerners enslaving black people. Nothing is said of the fact that the first slaveowner in the pre-USA colonies was a black person named Anthony Johnson, or that free blacks in the USA often owned slaves, or that black slaves were purchased from black people in Africa, or that the very term "slave" comes from the white Slavic people, or that black Africans are still being sold today, or that enslavement (generally, and particularly of black people) is endorsed by a major world religion.
Don't make it an us-vs-them thing, but unite them. Let them embrace those differences.
You can't stop human nature. At best, you can divert it to something less problematic, like nationalism. If everybody is on Team USA, then there is no room for racism.
We will never eliminate the urge to judge, rank, and exclude. It's very deeply in our DNA. All the social mammals have the urge.
Of course you shouldn't teach them self-hate, depression and that sort of thing, but you can teach black and white kids to unite against those old patterns that have kept them separate, to have them work together, to teach them they are equals.
I keep seeing too many excuses not to tackle racism, but that means it will continue to exist and hold new generations back.
You don't solve problems by ignoring them. Of course you should also not solve them by making them worse. So you should absolutely look critically at the way in which kids are taught about this, but it's important to make kids aware that this is something that has held previous generations back, and they shouldn't be held back the same way. Sheltering kids from history is not going to make them learn from it, and as we know, people who don't learn from history are doomed to repeat it.