indyank - 6:32 am on May 29, 2013 (gmt 0)
It seems like if Google came back around and saw that all that web spam was indeed gone
Nope,I don't thing it is about coming back to see those thin content pages are gone. It is more about crawling the entire set of URLs they have in their history DB for that site. This includes old URLs that you had removed years ago and URLs that never existed on the site.