No **** Sherlock. However, handlebar movement to initiate a turn at speed is negligible, maybe several degrees of rotation at most. So what would be the difference in movement of the end of the bar for a 100mm stem vs. a 140 mm stem to facilitate 1* of rotation of the fork? Different stem lengths would only effect the amount of input into the bar to cause the wheel to turn, not the actual geometry and handling characteristics of the bicycle, unless the change in stem length where so great as to change the balance point of the bicycle by a substantial amount, which again is possible, but unlikely.

Unless you make a huge change, you are not going to be able to tell the difference.