If I understand correctly, these “dark points” are a systematic consequence of waves - an observable effect from the wave [interpretation] itself.
For it to 'travel' faster than light, it must be a specific kind of property and phase alignment between waves.
I would love an animation showing this. Given that it is possible, I imagine three or more waves could lead to the visibly 'traveling' zero amplitude point, and it would be quite obvious and followable how that 'point' can travel faster than the waves are.