This is what I was getting at, also.
However, I do not think very much of your argument that the children's dead parents are going to corrupt their souls. The question wasn't whether to fight for freedom and kill white plantation owners--the question was whether to also kill their children, regardless of age. (And the non-slave-owning whites. And their children. Including after the French had been defeated and the few remaining white people were in hiding.)
I don't know what courses of action were practical--maybe there wasn't any good way to save any children given the volatility and uncertainty of the situation. And without reading more, I can't judge what people reasonably believed at the time about the innate character of races.
But I'm pretty sure that if the proposition is, "If you have the misfortune to be born the child of a parent who is brutally enslaving people (or of a parent who isn't, but has the same skin color as those who are), you deserve to be put to death," there is no way to interpret that from a modern perspective other than as both savage and cruel.
And yet, such is the nature of terrible situations that at times, savage cruelty is the best one can manage to avoid even worse savage cruelty. However, it is the nature of progress to be glad we have escaped such terrible times and to forswear such cruelty ourselves--and sometimes to identify past opportunities to avoid cruelty that could have been taken then, but weren't.
(Starting, of course, with don't set up a barbarous high-mortality-rate system of slavery even if people will pay a lot for sugar! But we needn't stop there.)
(Edit: a good continuation, for 1804 specifically, is "Once you have all the power, genocide is not a superior solution to exile.")