What would happen if the concentration of h ions were higher inside the mitochondrion than outside the mitochondrion when the channel opened

If the concentration of H ions were higher inside the mitochondrion than outside the mitochondrion then the H ions would move to outside the mitochondrion to equalize the pH of both inner and outer side through the opened channel.

In mitochondria H ions usually move from mitochondrial matrix to inner membrane of mitochondria by active transport. This generates an electrochemical gradient due to the low pH in the mitochondrial membrane than in matrix.

This gradient allows the H⁺ to flow back into the matrix through ATP synthase which generates energy in the form of ATP and equalize the pH both the side.