We have not characterized the expected life of those regulators, but in general I expect them to work for many years unless they are run near their limits or otherwise stressed. What operating conditions do you expect?
If you want to think about these things, you should get a thermal imager to see how hot which points are getting in your actual application. The imagers are getting much more affordable, and you will see not only how hot things are getting but also how much various heat removal strategies are working.
The inductor and the regulator IC next to it will be the hottest components. The most constraining part (the one getting hottest) moves around depending on your operating points, but on this particular regulator the IC is generally hotter than the inductor.