Hello, another current TWU Dallas student here! 🙂
I'm not sure how structured their method for placing students is, but I've heard about a variety of scenarios. Dallas is generally more competitive, possibly due to a larger amount of applications that specify "Dallas only/1st choice Dallas". This is my own speculation, though!
I was waitlisted the first time I applied--Dallas was my first choice, but I was later offered a Houston spot that I rejected for personal reasons. I know of someone who was waitlisted (1st choice Dallas), later offered a spot in Houston (which she accepted), and eventually offered a spot in Dallas. I feel like they try to accommodate personal preferences as much as they're able to, but it really helps to be flexible.
If you end up being waitlisted, don't be discouraged! Quite a few of my classmates were given a spot in Dallas in June/July before the semester started! They're all incredibly smart individuals, some of who actually have some of the best grades in my cohort.
Also, hello hopefullonghorn! 🙂