... remember the roll is due to a change in inflow angle, not a massive amount but enough ...
It is also accompanied by vibration, because the inflow angle only changes at the front of the rotor disc and the effect is assymetric until the airflow regime for forward flight is established. In a normal transition from the hover to forward flight the vibration may not be noticed.
However, if you have spent endless hours in the hover in a SeaKing over the Atlantic with a strong breeze (25+ knots) blowing you cannot ignore it. That is firmly in the vibration bracket and it manifests itself by shaking the body so that the fleshy tip of the nose wobbles and tickles almost unbearably. ;-)