I have seen MV cables specified as a minimum length (In that case 100 Feet minimum) to limit the ASCC to the rating of the switchgear.
The extra cable was looped in the cable tray.
The image didn’t load for me, but looping cable in a vault means that when a termination or splice fails you still have cable to do it again without needing to splice in an extension. Termination/splice failures seem far more common than actual cable failures.