Basically, the way it works is you interview at TX schools (Baylor not included.) Once you're done interviewing, you rank the schools according to which school is your top choice, second choice, etc. Then, the med schools numerically rank their applicants. After that, there are 3 possibilities:
1. You get into the school you ranked the highest. You are automatically withdrawn from the schools you ranked lower.
2. You get into a school other than the one you ranked highest. You are technically waitlisted at the schools ranked higher than the one you got into and withdrawn from any schools ranked lower than the one you got into.
3. You don't get into any of the schools you ranked (interviewed at.)
So the system basically keeps you from holding more than one acceptance at a TX system school. It actually makes a lot of sense and prevents the inefficient system that many AMCAS schools adopt of waitlisting a bunch of applicants and making them wait forever only to eventually accept them.