The child doesn't consent to a life of being outside of that social norm. One could make the argument that it's in the same ballpark as raising a child in religious extremism.
And just to play devil's advocate against that argument in turn... the child didn't consent to being born. In fact, in most existing legal systems, children don't consent to much at all until the age of consent. And arguing that giving birth to a child without abiding by all social norms is immoral is an extremely slippery slope in and of itself. At least eugenics was (ostensibly, of course) concerned mostly with measurable traits, this is arguably worse.
I know you were playing devil's advocate, but that argument can be said of any child. It's functionally slavery to be born in Africa since the living conditions are terrible. It's functionally slavery to conceive a black child in America since it's statistically likely to be poor. It's functionally slavery to have a child born to rich parents since there is a high likelihood of emotional abuse due to drugged out mothers and workaholic fathers.
That is an absolute cavalcade of stereotypes. Even then it has a major hole. In your vision those children will still be born into the societal norms of their larger group.
Then we shouldn't allow gays to breed with lesbians to create a timeshare child. The same is true that the US should have actively stopped the intermarriage of blacks and whites for the same reason. India needs to stop the procreation of Christians since the social norm is Hindu.
An absolute false equivalence, save the "timeshare child" thing, which sounds disastrous for the well being of the child. Nobody in their right mind would argue that a child split between two homes is a preferable state. Regardless, there was no argument of banning anything made, so you've descended into hyperbole.
Would you not want to ban slavery? Do you want to keep these scientifically created children in their chains as the OP suggested they were in? You monster!