Matthew,
I've been told the same thing by a different cable company. When reading the writing, the flow is left to right.
As for the "learning" the direction, I've heard that as well. While electron flow over time will affect the grain structure and stresses, It would take a LOT of continous current (high amperage) and building up of heat to completely alter the structure (i.e. annealing the metal). Minor changes (key word being minor), that is dependant on the material, impurities, and initial grain size, but does happen. Thus the infamous cable "break-in" period.