I ran this by Dr. Chang via email, and in typical fashion, he replied immediately (he's amazing!).
He indicated I'm understanding this research correctly but there is a catch: the first few millimeters of cranial nerve, where it exits the brainstem, is typically not myelinated. So remyelination along the rest of the length would not necessarily help if the tumor were large enough to reach and damage that section close to the brainstem (or if it originated in the cerebellopontine angle close to the brainstem, as a small fraction of ANs do). In that case, the electrical continuity would still be degraded. Put in plain English, metaphorically: if a wire is broken on one end, it doesn't matter if it's repaired at the other end -- it would still not pass signal.
The takeaway is that this groundbreaking research does hold some promise for helping people with ANs recover some function in the somewhat distant future, contingent on where the nerves were damaged.
Exciting!
Best wishes to all,
TW