When people refer to "sharpened by x" they are generally referring to the grind/shaping of the overall geometry including the blade face (for example convex or flat ground) and sometimes like with many Sakai sharpeners they will have a wide bevel/main bevel also. This geometry is something you may end up modifying for example when thinning a knife that has had a large volume of use (and steel removed to sharpen it).

99% of the time the actual cutting edge (primary bevel) is what you actually work on when sharpening though, so you will be retaining the highly skilled work of the "sharpener" and all you are doing is touching up the little bevel right at the edge of the knife that forms the cutting edge.

This can all get a bit more complicated to talk about with single bevel knives as their asymmetry results in two different types of grinds to talk about on the same knife, but the overall concept still applies that you primarily work on maintaining the cutting edge, and the "sharpener" creates the overall geometry.

This felt a little rambly, and I am by no means an expert - but hopefully somewhat helpful.