Currently the Villager.Professionhttps://hub.spigotmc.org/javadocs/spigot/org/bukkit/entity/Villager.Profession.html#NORMAL class has two values which seem to be unused: NORMAL and HUSK. Husks are currently different entities and therefore aren't a villager profession. Normal seems to be used for zombie villagers/zombies, but both entities are currently two different ones (as the methods relating to villager professions in the Zombie class are deprecated) and zombie villagers and villagers require a profession which means that normal wouldn't be possible.

 

My suggestion is to deprecate those two fields as they don't seem to serve a purpose anymore.