My guess is that it both gets rid of a chippy edge and gets to better steel.
The times that I have killed an edge come from seeing chippiness on the edge when I have finished my regular honing routine to 16k.
I use an aprox. 500x scope to look at my edges. Once in a while the edge still looks chippy no matter what I do or how long I do it. Killing the edge and going back a step or two on the stones, then working back to finish has pretty much always worked for me in bringing back the total smoothness. Only on the rare occasion where there is deep pitting and really bad steel does it not work.

Pete <:-}