When we stayed at the AKL we had both in the room. I am allergic also and called down for new pillows, they arrived in about ten minutes and we did not have any problems. My parents, who were with us, stated on their reservation that they could not have feather pillows and they had fiber filled when they got to the room.
I always let them know that I need non-smoking due to asthma and non feather pillows. They have been very good at filling the requests. We changed rooms at the AKL that is why they didn't have the right pillows. The first room they put us in had fiber filled.
For Medical reasons they try very hard to fill the request.