I get that "promise manufacturing warranty" isn't crystal clear. But you don't think the opening phrase "Our blades are designed for longevity and to endure the stresses of world-class competition." clarifies what is covered? Surely any reasonable person would assume they are warranted against breakage, if it went to court? And many pro shops routinely successfully return (new) defective blades to HD Sports (which makes MK, Wilson, Revolution blades).
It might be interesting to see what would happen if someone sued HD Sports after a blade broke in competition - not just for the cost of the blade, but for the value of the assumed Gold Medal they lost by a very small number of points. A true public relations nightmare for HD Sports.
Anyway, lifetime warrantees don't always imply maximum quality.
For example, hand tools from Sears Craftsman, Husky, or Harbor Freight - low end "professional" tools - have a lifetime warranty. At least with Sears Craftsman, if they haven't changed, you could break a a screwdriver by using it as a cold chisel, then return it, with no receipt or explanation, and get a new one. OTOH, really high end professional hand tools, like Ideal, Klein, or Snap-On, do not, AFAIK, have a lifetime warranty - because they know that nothing can stand up to severe abuse.
Similarly, a lot of skate techs say that Jackson Ultima is much more consistent than HD Sports at shipping unwarped blades with consistent profiles and edge shapes (one of the reasons some shops prefer them - though the higher retail price mark-up helps a lot) - but they advertise no warranty.
I don't think any major brand of ice skating blade would accept the return of used blades for rust, wear or scratches.