Highly likely it’s not. Unless the applicant is some form of “special interest,” meaning that they have people who are donors interested in their admission, connections to the law school itself, etc. you really wouldn’t defer someone just to intentionally deny them later. That isn’t doing either you or them any favors. Rather, you defer them to see how your numbers look throughout the entirety of the cycle.
At some point almost every school, including T3, will say “our medians look like x and z, let’s take a look at those candidates we deferred/WL’ed with the amazing softs,” which is precisely why you should have a plan for how to work the waitlist persistently, professionally but not pester-y. With apologies to the alliteration, that last sentence is exactly what getting admitted off of the WL is all about.