What were these industrial changes you speak of?
If the Civil War had never happened slavery would stll have been on the way out and fairly quickly.
I'm not aware of any quotes from any Southern leaders prior to or at the beginning of the Civil War that indicates they believed that.
Its just the way history was evolving and did evolve. Mechanization was on the way in and came in fairly quickly. There is not a lot of room to argue the Industrial Revolution.