Hi, Id say as replacing the cam chain is not included in the maintenance schedule I wouldn't worry about it. It could well last the life of the engine but it really depends on how the bike is ridden and maintained.
The only time in over 30 years of riding I have had to changed a cam chain was when a cam chain tensioner failed and went unnoticed until I went to adjust the valve gaps on a well abused 60k mile z750e.
And if you ask a dealer make sure you are sitting down if they give you a price for changing one as it involves a total strip down and rebuild of the engine.
So unless you are planning on doing some serious work on the engine (big bore/ gas flowing/ blueprinting/ nitros....) I wouldn't worry about it - just enjoy one of the most ridable, well mannered bikes around at the moment.