Uniform

Relevant wiki: Heat Transfer

Initially let us assume that area of hole decreases due to area expansion of metal sheet. As a result, atoms on edge of hole come closer on heating. But this situation is not possible as distance between atoms increase due to higher vibrations of atoms as it absorb energy due to heating. So area of hole also increases, i.e., radius of hole increases. In general, every area expansion due to heating is like photographic expansion.

Imagine you took the metal plate still integer, cut that hole yourself and then heated up both pieces separatedly to the same temperature. Whenever they are at the same temperature, the piece you took will still fit on it's original place.