How would you have written Wall-E, especially how the humans were handled, without the fatphobia?
Honestly just...make the humans have different body types. If you want to make the point that they're weak from bone density loss, well, that's not going to look like Fat on every body. Just like not every fat body is weak (that's a laugh- I know fat people who could yeet me across a room without a thought).
Although given the internal logic of the Axiom just not making sense, some of them probably SHOULDN'T be weak from bone density loss. They should have ways to counteract that- they do now, for astronauts -and there's no reason for BnL to want them physically helpless. They don't need to be; they gave the company control with all the body and strength diversity of modern people. I'd probably make their behavior the centerpoint of the commentary.
I might show them being unable to make decisions without being told what to do by the ship's computer, like the "try blue- it's the new red!" part in the actual movie. Or giving up immediately on new tasks if they encounter the slightest bit of difficulty. I could leave in the constant staring at screens, too- make it hard or them to pull themselves away even when they want to.
It was really an easy point to drive home without making a certain body type shorthand for laziness and lack of agency.
