I am envisioning a joystick that is simply sitting up in the air. Pick one for your favorite game. Hold the base. Now move it rapidly left and right. What is the effect as read on your computer screen? Does it stay put? Does it move as if somebody had their hand on the stick and was exerting control?
One would hope that the sprung self-centring of the joystick versus the movable part's weight with no hand on it would far exceed the transient g-forces available in flight to move it on it's own?
I have no experience of the A330 stick, but I assume it's got to have a certain amount of sprung(?) self-centring otherwise it's one hell of a choppy ride when the pilot wants to scratch his chin.