Honestly, weaponizing space is about as stupid as using nukes to advance policy. The long term downside just runs off the chart. Can you imagine what zapping a few good size satellites would do to create ultra high muzzle velocity space junk that would put EVERYTHING in space at random risk of destruction?.
Although we should consider keeping space junk free going forward, I think the probability of what you're implying is insignificantly low. First off, the sheer surface area around the exoatmosphere at any given altitude is enormous compared to the size of any junk in space. Then, you have to consider that both items would have to be at the same altitude to collide. It would be like shooting a bullet in a rural county area in a random direction and accidentally hitting a man 4 miles away center mass.
