That’s impossible to predict because every program is different and every applicant is different.
I will say that in my own opinion when I was reviewing applicants for residency after years ago, class rank was more informative to me than GPA. The grades at the institution I went to for residency were significantly inflated compared to the institution I went to for vet school…at my vet school my GPA was a 3.2 and I was 53rd percentile in my class. At the school I went to residency at, a 3.2 would have been very bottom of the class. When writing exam questions for lectures I taught I was told we were aiming for at least an 80-85% average grade, which certainly wasn’t the average at my vet school. Class rank is more useful to show how you performed compared to your peers. Someone with a 3.2 and 53-percentile at school A is arguably slightly “better” than someone with a 3.2 but is 84-percentile at school B. And that’s without factoring in schools like Illinois which do that one-grade-a-semester thing which stacks up differently against people who get a grade for every single class, someone there may have a 3.2 and be like 30-percentile or something. That’s why class rank means more to me than GPA. But even that isn’t the end all be all metric by any means.
If schools aren’t going to track and provide GPA or class rank info, you can’t give a program info you don’t have. Some schools may have people who can’t emotionally give up using GPA, others will adapt and just have other factors weigh more. Neither is necessarily better…in your question you ask if it better to just have a pass vs an average GPA? Potentially. But does having it just say pass make it better for someone with a below average GPA? Probably. Will places take a person with a GPA over a “pass”? I’d guess probably not but who knows, especially in the early years as people learn how to judge applicants without that info. There’s a LOT of old school specialists who believe you need a high GPA to be successful on boards and that sentiment isn’t going to go away overnight. But it’s one of those things that is what it is, and programs and applicants will both have to deal with it.