Ah, I bet you’re right. It fits with what I found when I searched “hail suppression cannons”. I’d never heard of them.
An interesting note from Wikipedia:
all manufacturers unanimously agree that the area of effect of their device is only 100 to 200 square meters directly above.
Given that serious hail is usually propagated by severe thunderstorms, what are the odds the hail will fall straight down? Remember, the volume it forms in is many thousands of feet up... (In fact, in a hailstorm I was in, in Kansas, windows well under the eaves of the house were smashed by large hail -- some hail ended up IN the house.)
I rather highly doubt these things can disrupt hail formation anyway.