This isn't a case of the "new satellite failing", but rather the new satellite deciding to self destruct an hour after it arrives. The entire point of the mission would be to deny use of the entire geostationary for everyone.

If a satellite has several tons of ball bearings and simply releases them, they will over a day or two spread over the entire orbit.

There has already been a two confirmed debris collisions in geostationary orbit, with another 20 suspected. This was a case where it wasn't intentional. Imagine 3 or 4 tons of steel balls intentionally released into that same orbit on purpose.