I can't speak for the OP, but large scale playback systems using spatialization techniques such as Higher Order Ambisonics or Wave Field Synthesis require this many outputs (and potentially a lot more).  But really any distributed playback system that goes beyond the limits of consumer-oriented 5.1 or 7.1 standards would take advantage of having a higher number of outputs, especially if multiple cards can be chained and synced. For the price, these cards look to be an economical solution for such a use case.