Today I decided to give Zos the benefit of doubt and finally upgraded my werewolf form again (while I was in Imperial City PvP zone) and immediately it reset back to its basic version, while still consuming my skill point.
I read a post about why the skill points were not being refunded, so I thought that at least the resetting of the skill should be fixed.
I really hope it gets fixed along with the next major patch, because otherwise the skill points reset will be useless, as players will immediately lose a skill point right after they attempt to upgrade their lycantropy.