I have never once heard of this happening. Job candidates passed the boards which is the most objective measure of their competence. I graduated from a brand new program in an inaugural cohort - highly reputable school but brand new program - and had several job offers as soon as I graduated. None of my classmates had issues finding jobs either, and I have also never heard of anyone having a problem locally or on these forums.
I have heard of difficulties getting jobs if you went to PT school outside of the USA, where standards are different from what I understand. This is what I have heard from local clinics, but I don't know much about it.