It should be noted that MD, MO, WV and various other states excluded from the Emancipation Proclamation freed their slaves by state action befoe the end of the War. The 13th Amendment freed slaves only in DE (a couple hundred) and KY (around 50k).
While this is all interesting history, all of the slave-holding Union States had emancipation plans, held in abeyance until after the war.
If you are going to make such an astonishing assertion, you need to be able to prove it.
For it to be true, one would have to assume southerners were all really, really stupid.
Any intelligent person of the time knew that the South's best hope for independence was foreign, particularly British, recognition. British public opinion was unaminously anti-slavery. As long as the War was between a pro-slave Union and a pro-slave CSA, British recognition was conceivable. Which was precisely why Lincoln issued the Emancipation Proclamation. At a single stroke, it ended the possibility of UK recognition.
Intelligent southerners knew that passing laws for emancipation, even very gradual emancipation, would immediately revive the chance for foreign assistance. Yet it was never seriously considered.
IOW, given the choice between slavery and independence, the South could not choose, since the reason they insisted on independence was to protect slavery.
I'll await your evidence of state plans to abolish slavery after the war. I suspect I'll be waiting a very long time.
Confederate generals Patrick Cleburne and the great Robert E. Lee were for plans to give freedom to slaves who fought for the South. They were given a hearing and summarily turned down. Because freedom for slaves was against what most Southerners stood for.
I don't know if the South could have found enough slaves to fight for them with their freedom as a prize, but the fact that Cleburne and Lee were given short shrift proves what the South was fighting for...slavery.