I thought the consensus was that McFarlane isn't one of us, as he has the Orville yet no fat women in that show, even as a punchline. Nor any plots related to feedism.
I figured one or several of the writers on Family Guy/American dad is/are one of us and just use fat women as jokes/punchlines because it's the only way they can get away with showing fat women in fiction.
It is possible there are FAs in Hollywood, they just can't get away with doing a lot of fiction that shows fat women as they have to work on shows/movies which are collaborative and may not allow one to get away with inserting their kinks in it. Like if I was writing episodes of a TV show and want to have more BBW characters/feedism/etc. I doubt that the other writers would be comfortable with me writing my kinks out and wanting to do it constantly. Best case, we get an episode or two with plump women presented as sexy and having some feedism. This is what working on collaborative projects means, we don't always put in the stuff we want and we have to listen to other people's ideas for episodes and work their ideas in.