Loss of audio on a folddown is more likely to happen if the sound is centered, not if the sound is panned hard. That’s because the centered sound would be in both channels, but could be out of phase. Then when combined it would disappear. A hard-panned sound would not be cancelled, it would just be half as loud. Also would need to know the frequency of the chain sounds… the non-Leia examples are really quiet and high. So I would retain some skepticism until more examples are found.
A smoking gun would be a sound effect in the optical audio that isn’t in the stereo mix.