Bullets fired at any verticle angle will fall 'ballistically' which is a fore-shortened sort-of-parabolic curve due to air friction. If the angle is large, then the fall is essentially at terminal velocity. A shot at a drone is likely to be at a large angle.
The reports of 'celebratory gunfire' deaths are all necessarily speculative - the angle of the shot is impossible to measure. We can resort to physics to get a better answer than that derived from headlines.
A close friend of mine was killed by a stray bullet this year at a 4th of July celebration. She was in a crowd of thousands of people gathered to watch some local fireworks. The shooter was miles away and probably has no idea that they murdered someone.
