Sure, I'll disagree with you. From experience, I can say that a never used chip will not OC as well as one that has been used for a while. Try it yourself, next time you get a new chip.
There is some basis to believe that heat will allow for some micro-transmigration of conductive particles in ICs. The net effect of this would be minimal.
Where the most advantage comes is in copper interconnects, bothe on chip, and on mobo. The "patina" that develops with heat is important to conductivity in a DC environment. Since hole flow in DC is more active on the outside layers of the conductor, and a good "patina" has been shown to enhance this conductivity in DC machines, it seems realistic to believe that the conductors in a computer would similarly benefit. It seems reasonable to believe that the enhanced conductivity would yield a higher potential speed, by preventing communication errors.