Looking on all the discussions sprouting up, I think in both the short term for political expediency of reconstruction and in the long term of the south as a whole to spare itself perpetual self-loathing the Coup is critical. In ITTL argument:
the pre-coup confederacy was for a foolish and downright bad cause but many behaved nobly (guys like Lee or Longstreet for example) and the leaders like Breckenridge stood up to the evil planter elite to fight for the average man that thought that secession was a representation and declaration of a shared southern culture rather than a tool of the Slaveocracy to stay in power. As the war was clearly lost and those of the noble persuasion realized it and tried to get the best peace possible, the Slaveocracy threw off their mask of southern pride and revealed themselves to be what they were.
This argument is filled with distortions, obfuscations, and convenient lies but the kernel of truth is in there and makes for a heady way for Lincoln and the Union to focus hate on the Junta (I mean, the starvation and Jacquerie and the futility of fighting and the kangaroo justice involved pretty much makes it easy even from a southern pov) while portraying the pre-Junta as wrong and criminal but still having "honor." Such a distinction is not a dividing line given that Toombs and the men he killed all shared the same disgust with abolition but I feel the distinction will be viewed as bright by the vast majority, especially in the south.
I see a lot of class distinctions coming forth, maybe the Lincoln admin trying to connect the plight of the slaves with that of the poor southern whites: "The Slaveocracy didn't care about anything but their own power" to counteract claims of white supremacy. Toombs executing people to preserve his wealth and Joe Johnston/Beauregard executing people to settle political scores while stirring up racial hate as a justification while seeing all the poor of all races as just cannon fodder.