It’s irrelevant to what I said before. Whether some Confederate leaders decided after three years of war that giving up slavery was a price they were willing to pay for independence does not answer the question why the Deep South seceded in the first place.
Besides that, there was substantial resistance in the South, notably in South Carolina, to enrolling black men in the Confederate armies even in 1865. The Rhetts, for example, insisted in The Charleston Mercury that the war was in defense of slavery, and so giving up slavery to win the war made no sense. Georgia’s Governor Joseph Brown made similar statements. I am not saying that this remained a majority position in 1865. We don’t know. The idea of giving up slavery was certainly very far from Deep South politicians’ minds in 1861, however.