I found the respective paragraoh under PSA’s Terms and Conditions:
I find this totally misleading: the Reholder service is presented as not a re-grade as long as the holder hasn’t been altered or damaged, i.e., you’re paying for a new case, not a new evaluation.
But then the fine print reads like PSA can reassess and change the grade at their discretion.
And for collectors, it’s such a brutal risk: you can spend years building, say a PSA9 collection, and then get hit with surprise downgrades just for wanting a clean slab.