timing chain replacement

[BK]

"Why would you want to?  They are basically a *ZERO* maintenance part.
I've
got 367,000 miles on the stock chain.  No problems."

I realize it's a different motor, but I had a timing chain break on a GA16DE at around 100K miles for no apparent reason (wasn't driving hard, not even at highway speed).  It had been rattling around for weeks before it went.  A mechanic informally advised me "not to worry, timing chains won't break.  They might develop some slack...if they develop enough to skip a tooth then you need to replace them"
Just my $.02
Brian in VA