Probability of a freckle on any limb is going to increase with age. I'm 4/4, maybe 8/8 if you count both sides of each limb. So yeah, pretty good chance that others born before 1990 are going to have a freckle there.
It was a slower roll out, y'know logistics and all. Can't just snap your fingers and upgrade hardware on saucers in other solar systems, even for them! Had to install them when the saucers went back to the shop for the regular service checks.