I'm not sure where- but I'm pretty sure I remember somewhere Cutter having it impressed upon him that knowing his soul name from birth was rare and special- and that he had to keep the name private and not share it with anyone. That might be in the prose BoTC short story collections... i don't remember exactly. So maybe the same was true of Dewshine and Tyleet. Maybe they were all atypical. Or maybe the younger generation of Wolfriders is simply changing.. yet again.