It’s not to replace them… they are planning on a certain portion of DA students not getting through. Some programs do not have the ability to provide clinicals for as many students as they admit.
As has been discussed here on CC, U of Rhode Island is just an example of such a set-up. Not so much weeding, but the program includes an “out” in the fine print to not let even the direct-admit students with high GPA the opportunity to progress through because of a shortage of clinicals and/or space in upper-level classes. There is a secondary, competitive process to progress through the supposedly DA program at URI.
This turned my D22 off- she loves it and was admitted, but wasn’t willing to chance it and worry about this stress of not progressing EVEN with the necessary GPA.
Then there are plenty of (MOST) DA programs that do not allow transfers at all… no intention to replace those who don’t make it. Most are clear about that.