The issues as I see them would be as follows:
Weight - these are going to weigh at least 1 oz - likely more. I think you'd quickly reach most drone's carrying capacity with relatively few "bombs." This would necessitate many trips to cover even relatively small areas.
Structural integrity of the "bomb" - depending on soil structure and moisture content, these could "bombs" could break on impact even from relatively low altitudes. The point of the "bomb" is that in it's initial configuration it can hold a fair amount of water - enough to facilitate germination. If the "bomb" ruptures on impact with the ground after being dropped from a drone, then you would be left with seed and soil sitting on open ground and would lose the benefit of the "bomb" in the first place.
Distribution - spacing isn't all that imperative if you are putting out enough of these things, but even limiting delivery to a defined space will be difficult. The GPS in most drone are not precise enough to permit landing your "bombs" within a 1' area, so you'd probably want to seed at a higher density than required.
Does the drone have an apparatus that would release single or several "bombs" at a time - rather than the entire batch at once?
I am interested to know why you would want to plant with a drone rather than just walk to the area in question to plant - unless you don't have access to said area for some reason or don't want to be associated with any kind of planting occurring at said location.