This might be a good question for Laurel, but I will try my best to answer.
To my recollection, much of the waitlist movement occurs at the end of the cycle. This is because, at that time, students with multiple acceptances are narrowing down their list to plan-to-enroll and finally their commit-to-enroll programs. The wonderful and really humanizing thing about applying to UCF Med is that, historically, admissions will tell you what quarter of the waitlist you are on and historically the odds that someone in your position will be extended an offer. That is not to say that WL movement ONLY occurs during that period- I believe it is just more likely.
Hope that helps!
Edit: I remember how tough the waiting period was during my application cycle. We put in so much time and energy during this process - ECs, LORs, secondaries, interviews. It is normal and common to feel anxiety during these days. However, I will encourage you to enjoy this time to the fullest extent you are able. If you are a traditional student, enjoy your Junior/Senior years (some days I look back on undergrad with a sense of nostalgia). If you are a nontraditional student with gap years, enjoy any free time you have by taking up a hobby or watching a movie or binging a show. And please do not feel the need to study/prepare for med school at this moment, you will have more than enough time to study medicine when you're here lol