Marquette rather stands out as an example of their admission practice.
In the past Marquette reviewed all appl received prior to Sep 1 and sent invites in big batches mid Sep- 200 for OOS and 100 instate. I am not sure if any additional invites were sent after that and school was practically filled by Dec 1.
Most schools do specify they review appl in the order they were received. Many will send invites in batches as they review them and some will trickle in few invites per week. BU and NUY sent their first big batch of invites couple of weeks ago to people who had application complete June- July and now working on those who applied in August...
Case is better example to understand why early applicants have better chances. Case starts interviewing as early as July so those people who applied in first batch get early invites. Case does reviewing the files in order so those who applied early, get their response early. It is Numbers school mainly- got GPA above certain point and DAT above certain point- got the interview. It is somewhat simplified view of course but main reason for rejections, which are sent early, are low GPA and to less extent DAT. Following the application cycle you could clearly see which AADSAS mailing batch they are reviewing and who is receiving responses. People who applied late in July and August did not get pre Dec interviews. I believe now people are scheduling for March. So come Dec 1 people who had pre Dec interviews will be in good shape as Case will probably send enough acceptances to fill the class. Those who receive acceptances by Dec 1 will have 45 days to decide whether to send their checks or not. Come Jan 15 or so second round of acceptances will follow. Since Case has been known to get over acceptance in the past I am thinking they will be sending those acceptances in the small batches until they have enough to fill the class. So more likely than not people who scheduled for interview in March will be interviewing for wait list spots.
I believe Nova, Indiana and Midwestern have already filled their pre Dec interview spots so anyone who is applying now is at disadvantage.