(Sorry for being naive) What is the discovery of this finding - is it the Chemistry of reprogramming the cells or a spontaneous way to evolve these cells back to their original code?
What do you mean by a "spontaneous way to evolve these cells back to their original code"? The cells' genetic code (DNA) itself not changing, but not every gene in a genome is expressed in equal amounts or at the same time. In addition to encoding genes that "do stuff", the genome also codes for helper molecules which regulate the expression of these "action genes/proteins" in response to stimulus and environmental conditions. Modifying or replacing these helper molecules can therefore change the fate of the overall cell without even touching the main "action genes".