Read it carefully, man. It says:
"​A replica weapon is a reasonable facsimile or copy of a weapon, even if it is not capable of discharging a projectile or substance..."
So a replica weapon is one that is a reasonable facsimile or copy of a weapon, regardless of its ability to discharge projectiles or not. Remember that all G1 Megatron reissues (and eHobby Megaplex) are capable of shooting projectiles in gun mode, and they are absolutely classified as replica firearms.