Yeap. No yelling or noises in Wing Chun, just breathe naturally. Heavy exhaling breaths in Boxing and Muay Thai but no yelling. Kali, Silat, Tai Chi, and JKD are all systems I've train and we didn't have much as to yelling in any of them.
I think you should do what your style teaches, you don't start changing things around because you don't like or understand one piece of what you are being taught. Not doing kiais in karate would be as bad as doing them in Wing Chun.