In chapter 385 Lucci states
You learn the name of the fruit when you gain its power
- so why did Luffy not learn the name of the Human-Human Fruit, Model: Nika after eating it?
- or did he mean you name the fruit yourself after learning of its abilities?
I mean Luffy didnt even know he ate a devil fruit. So it may be that Luffy didnt listen or Lucci was wrong or the DF is sentient and itll tell you whatever it wants.