Lawyers told them to say that. In the same paragraph they note that their carbon forks should outlast aluminum, steel, ti, whatever.

Wound Up[SUP]TM[/SUP] forks withstand fatigue heroically, and should last much longer than steel, aluminum or titanium forks. Because of their unique filament-wound construction, they should also outlast other carbon forks. While exact lifespans are specific to a given rider and her or his riding habits, we usually see our forks lasting for more than a decade with fairly heavy use. However, since we cannot know your personal riding patterns, we cannot specifically endorse your using it beyond eight years. Or, if you like, 40,000 miles. That's why we offer our courtesy replacement program. If it's old enough for you to ask, don't risk it!