Undoubtedly good news that they're phasing out those PFAs that we KNOW are bad, but, I think you're onto something here.
The short answer is that the science is in its early phases, but, the replacements do seem to bioaccumulate, although are(perhaps) less toxic.
Some replacements:
https://www.bvna.com/insight/pfas-replacement-compounds
Some of the science about them:
https://esaa.org/wp-content/uploads/2021/02/ET2020-Obal1.pdf
https://echa.europa.eu/documents/10162/3ef82c03-e698-ccec-9a56-65a9491d20b4
https://www.sciencedirect.com/science/article/abs/pii/S1438463916305685