Assuming the cable is rated for the sudden force changes and won't get split into a whole bunch of smaller pieces that will drop at just their terminal velociti

Assuming the cable is rated for the sudden force changes and won't get split into a whole bunch of smaller pieces that will drop at just their terminal velocities. Think a shower of cable pieces rather than a whip. Not great, but it's likely that most of the energy will be dissipated by the atmosphere.