Yes, some schools are more transparent than others. For example, Fordham makes their policy clear–if you don’t get accepted to Theater/Acting, you can still minor in Theater (while doing some other non-theater major) and still audition. And there is a “second chance” process for Theater minors to become Theater majors.
But I don’t know about UT-Austin. Their webpage didn’t make it clear to me. I do know that most Theater programs have a certain cohort size they aim for (e.g. UT-Austin’s is 35) and so then they extend offers of admission to as many students as they predict they have to in order to yield that many given that inevitably some will enroll while some will not. So let’s say they know from years past that they have to admit 50 to yield about 35. They might keep a wait list beyond that 50, I don’t know. I don’t see any problem with calling the department and asking.