All AAMC member institutions are MD-granting programs. So I believe the facts for "accepted students" are specific to MD schools.
That being said, I do believe mean MCAT scores for matriculants at MSU-COM generally have worked out to 26 - 28 for the last few years. Additionally, it is good to note that admissions states that they require minimum MCAT scores of 6 in Verbal, 6 in PS, and 8 in BS for consideration.
I would recommend taking time to make sure you application is good, as they do look at each part thoroughly (i.e., a specific adcom member looks at your file closely and presents you to the committee). Fit is important. You're still in good shape if you submit the secondary by early August. Of course, you should also submit it within the time frame they request in the e-mail.
Note that only two letters are accepted.
Edit: I only see that on the AACOMAS Info Book page now... and can't find that stated on the MSU-COM website. Please follow any and all guidelines as sent to you with your secondary! Things certainly are subject to change from year to year.