I believe low pop/hard to grade cards will not see too significant of a retrace. There is a strong desire among collectors to own something that is “scarce” and nobody else has. Im assuming since trophy cards aren’t flashy enough/too expensive, low pop PSA 10s of set cards appear to be the alternative.
If a retrace occurs, the first cards being sold will be the cards with pops in the thousands and tens-of-thousands.