Most makers, IMO and experience, would not consider that to be a defect.
When the appearance of firearm is very important to you it’s best not to buy site unseen. This type of thing varies with maker and time. Decades ago I would not buy a Colt site unseen because of the variations of the metal work. Colt’s bluing has been known to be among the best but the symmetry of metal left much to be desired.
I’ve had cosmetic issues with US firearms as well as a German made Sig and Walther. The Sig 220 was a very early version with Euro mag release import by a small importer with a dig on the top of the slide otherwise fit finish and function were fine. This could have occurred after manufacture. No burring of the frame rail area as noted by some late versions. The Walther P5, believe it or not, was not symmetrical on the left side toward the muzzle on the slide compared to the right side. A fairly easy fix because it only involved some metal removal on the left but the cold bluing touchup is not so great. Another P5 bought at the same time/place is perfect. My last bought new S&W 745 has the same issue as the OP and some other minor cosmetic issues and functions fine.
The Walther and S&W have one thing in common. They were among the last produced.