Yes, the drone was used to provide the precise ship's position to the missiles, and that allowed to almost immediately turn off the main radar of the missile launching battery, thus not allowing Russia to learn about its position and to strike back.
It is not even a speculation, it's a nonsense. Strike distance was between 50 and 150 km, ground based radar is useless against surface targets on that range. Neptune has an inertial+GPS navigation system with active radar on the final approach[1]. This is how anti-ship missiles are working.
