The manufacturers do hone and polish their edges. However, the final steps involve applying some type of coating to the blade. This coating makes the blade smoother, which is an advantage. However, the coating also makes the apex of the blade thicker and somewhat rounded, thus reducing sharpness. The thicker the coating, the smoother and less sharp the edge will be. As you use the blade, the coating starts to wear off exposing the apex in its naked glory. Thus, it becomes less smooth, but sharper.
The Personna Comfort Coated lab blues seem to have a particularly thick coating as implied by the blade description. With those blades, the change to smoothness and sharpness during use is quite noticeable. The Lab Blue blades tug at my beard badly during the 1st shave, but by the second are cutting smoothly.
Your theory predicts the blade will feel smoother with subsequent shaves. With Feather blades, I find the exact opposite. Although they are still sharp on the third shave, the edge becomes so rough on my sensitive skin that I have to change the blade.
Anyone who uses blades "one and done" may not ever detect the change in the blade during their shave, although the improvement in sharpness that occurs during the shave may help with the ATG pass near the end of the shave.
Looks like on the empirical blade tests (which were actually impressive), most blades did increase in sharpness after the first shave. With the exception of the Feather, which actually decreased. And most blades decreased in sharpness after the third shave, but were still sharper than a new blade, again, except for the Feather. So the coating theory just might be right! Alternatively, there may be sort of polishing of the edge occurring with the shave itself, until diminishing returns kicks in. I have several vintage Japanese katanas, and the edge is formed not by "sharpening" but by finer and finer polishing stones, the last no bigger than grain of rice. This could produce an edge geometry of 10 degrees, not far from a straight razor's 7-8 degrees (compared to a sharp kitchen knife at 20). Some strange physics going on....