It's been a while since I was involved in coaching oversight, but as far as I remember, coaches need to be registered with U.S. Figure Skating to obtain liability insurance through the PSA. So yes, in theory, Zimmerman could coach, but he would need to have his own liability insurance, which may be difficult or overly expensive to obtain given his suspension.
Separately, given that the victim's father is a lawyer, now that Zimmerman's actions have been effectively certified as negligent by Safe Sport, I wouldn't be surprised if the family brought a civil suit against him, which could complicate efforts for him to salvage a coaching career.