Exposure to illness/injuries are often the first experience people have with the healthcare system which can serve as a good start point for one's journey to medicine. In addition, the whole 'interdisciplinary approach' often leads to exposure of multiple specialties. For example, shadowing a family or emergency medicine physician could lead you to consider a specialty you previously didn't know you were passionate about
Stick with what is in your heart, not what you think the school wants to hear. The key is to convey your passion for medicine, why you are a good fit for their school, and what you have done to prepare for medical school (not necessarily the specialty you discuss).