I would tuck them back in-gently. The shoots will grow out of the ground if they have healthy roots!
Just my opinion-
Julie

I think it unusual if any Platycodon frost heaves as they have a deep taproot. Yes, more likely the soil sank around them or you hadn't planted as deeply as you thought. Mounding soil around it is a possibility. Replanting will likely delay growth and flowering (so what). Replanting in early summer or later will probably result in immediate death of the upper part of the plant, but the root will resprout in a few weeks.

Rick

I would just do what I need to do, cover or dig and bury deeper. I have found the plant to be quite tough, so wouldn't expect any problems.
jan