It is a marketing gimmick, but your description of the marketing gimmick is wrong. They say PFOA-free because they use PFOS or another analogue in their manufacturing. They are no more safe.
Just like with BPA free plastics that often have even higher levels of BPS, BPF, etc. or related compounds:
https://www.youtube.com/watch?v=QuMGc0EswTc
(exploration of literature and the plastic industry's move away from BPA -- as always with Nutrition Facts, Dr. Gregor is totally calm and uses no scare tactics)
Thank you for that addition. I was stuck on the gluten-free thing and you are right about the BPA-free thing - another area where manufacturers just switched to a different, bad chemical.