The badge for completing a track can be lost, apparently, if another exercise is added.
But we might want to have another badge for “Moving Target” if an exercise is added, and then something else if you complete the track again “Beyond the finish line” or something similar.
Student completed the track, we added a new exercise, track is no longer completed, they reported the badge was gone. I, obviously, do not have access to personally verify, but no reason to doubt that they do not see the badge.