Suppressing Fusillade – A unit targeted by a Skyhammer Annihilation Force’s Devastator Squad in the Shooting phase must take a Morale test at the end of the phase on 3D6, regardless of how many casualties were inflicted. If the test is failed, the enemy unit does not Fall Back, but must immediately Go to Ground. If the test is passed, the enemy unit is unable to fire Overwatch for the rest of the turn.
So if I am reading this correctly the targeted unit/units must make a morale test even if no models are killed?