This seems just completely wrong. The trend for drones is that features and capabilities are increasing and costs are decreasing because they're based on cheap software and cheap consumer hardware. The trend for unguided mortar rounds or artillery shells is that they're as cheap as they're ever likely to be at thousands of dollars a round, plus the cost of the gun and its replacement barrels and crew. (guided artillery shells or missiles are so expensive they're a separate conversation)
If these small drones provide capabilities that are, as your comment implies, not new but they do it with a cost effectiveness that blows away anything that came before, that's a pretty big deal.