There may well be flights. Crew are exempt, so at least for slot-controlled airports it's probably worth flying anyway to keep the slot; you'll have some US citizens / permanent residents and their families, and you can fill the belly with cargo since you have spare weight. Might be worth it even for airports that aren't slot-controlled.
Here in NZ the largest airport with such slots has waived that rule for the duration meaning that airlines can reduce their flights without losing their slots (and therefore be more likely still be around to be a customer for the airport when it is all over)
Various aviation authorities in Europe are relaxing the requirements that is driving the slot controls & ghost flights. Don't have the link now but read it earlier.
