A replica is not meant to be an exact copy of the original.
If it is not an exact copy of the original and flies it does not prove the original was able to fly.
The use of the word means nothing, it may simply refer to the rotation.
"flap (flęp) vb, flaps, flapping or flappedto move (wings or arms) up and down, esp in or as if in flying, or (of wings or arms) to move in this way"
flap - definition of flap by the Free Online Dictionary, Thesaurus and Encyclopedia.
You have to show me an example (it could be 100 years old) where the word flapping refers clearly, beyond any doubt, to rotating propellers. You really want to be ridiculous. You are changing the meaning of words just to defend the hopeless case of the Wright brothers as the first people to fly an airplane.