Cryo is just a form of heat treatment. Heat treatment has been used for a thousand years to modify the properties of metals, as in swords. Therefore, it is entirely to be expected that Cryo will affect the tonal quality of brass instruments.
But, just because brass instruments play music, it does not follow logically that everything related to music will be affected by Cryo. But audiophiles are not known for logic.
But, just because brass instruments play music, it does not follow logically that everything related to music will be affected by Cryo. But audiophiles are not known for logic.