Nah, if you put too much on, it squeezes out under the mating pressure of the heatsink base and the core, along with the heat of the core. It may take a little longer for the base to settle down into its final resting position, but it certainly is not detrimental. Obviously, if you ladle it on like peanut butter, once it displaces, it could run down upon the cpu substrate.
Hoot