True. At low speeds, friction is proportional to surface areas in contact (and to the surface roughness).
To answer Tyrkon, we must make assumptions:
1) The CNC was actually set to remove surface metal around the corrugation areas rather than to add material at those locations (likely -- as you can tell by running your finger across the corrugated section).
2) The blade's geometry in the corrugation regions is basically rectilinear.
Then, we simply measure the height of the corrugations (on the deepest edge), the distance between corrugations, and the width of a corrugation. There seem to be 8 corrugation ridges. Staring at the blade with my eyes, I believe the material removed is shaped like a long, triangular prism. One can approximate the volume of such a prism by calculating the volume of a rectangular prism whose width is equal to the longest edge of the triangular prism (width times depth times length times one half = volume of triangular prism). Eight of these prisms would approximately equal the volume of material removed (not exactly, though -- take a closer look at the blade profile and you'll see this over-estimates). Multiplying this volume figure by the density of steel (all steels have a very similar density, I believe) and you'll get your weight savings.
When you're done, I think you'll find very little mass was removed.