Same way if you call something a "wing" it has to be a wing? (I think this should be a thing but since that's not true the boneless part isn't)
Edit: I said that badly, let me rephrase (and this isn't my opinion I'm just trying to decode the logic): Because "Boneless Wing" already isnt technically true to what the product is (it's not a wing), then the other part doesn't have to be technically true (it's not always bonless).
Now if someone sold, a boneless steak with a bone, then under this logic it would not be allowed.
I mean i would be fine with some spicy nuggets instead (just put the same flavor on and you have boneless chicken something, just need to find a nice name for it and done, ready for the menu).