My 2012 C5 does still have the stock chain on it. My neighbor he is a pro bike rider-mechanic said it and the sprockets actually looked good, and he is aware of the chain problems on the RE. I must admit the chain is absolutely slathered though, and it is adjusted.
He said to ride a bit before replacing it, because I have so many other expenses to meet at the moment. I don't ride very fast that often, and because of events, only about 400 miles since purchasing.