I guess he would because dropping Lieberman wouldn't have cost Gore any states that he won in 2000.
Eh ... to be fair, the butterfly effect might have flipped an extremely close state such as New Mexico to Bush in this scenario.
However, if the Gore-Graham ticket would have lost New Mexico and one other very close state (Iowa, Wisconsin, or Oregon) that the Gore-Lieberman ticket won in real life, then the Gore-Graham ticket would have still won the U.S. Presidency in 2000 if it would have won Florida (which is
extremely likely, in my honest opinion).