[2020] Mordhau community dev, Jax, suggested to add the rapier to the game when Mordhau was in pre alpha. That means most likely he is responsible for the addition of rapier to the game.

uh oh they've found out

in any case it probably wasn't "oh jax wanted a rapier we have to add it", like that's not exactly how feedback works. people give feedback and the team decides whether or not it is valid/gets added to the game :)