No, it's just normal wounds.
Things that affect Mortal Wounds always say Mortal Wounds in the description. As in something along the lines of "When you allocate a wound or mortal wound to a model...." And there's no errata for the 'Ardboyz' shields.
Wounds and Mortal Wounds are two different things.
So when in doubt read/play it the most conservative way. Maybe discuss it with your opponent.