I don't think there are that many true Switcher hitters out there for him to face. Not any decent ones I can think of anyway. The only ones i can think of is Junior witter and Carlos Maussa. Naseem hamed used to switch a lot too, but no-one in Kesslers weight division NB A switch hitter is someone who fight both orthodox and southpaw
there are about 4 or 5 true switch hitters who are any good. Its a useful trick everynow and again but few who use it effectivly Ward is one who does though so it could throw kessler a little
Of course Kessler himself is a natural left-hander, so who knows. The trick is to throw the uppercut just as they switch (the target becomes square on), so Ward needs to do it at a distance.