Not necessarily. I visit our local medical vampire every 3 months to drain a pint due to high levels of ferritin (hemochromatosis issues). I asked what they do with the blood. They destroy it by ashing it. The tech said they do this with any blood drawn from someone with a known disease state. So if phlebotomy becomes a common treatment for PFAS loads, I'd guess the draws would be destroyed. I hope.
Even if it did, the average blood/plasma recipient is more concerned about "not dying of blood loss" than PFAs.