I used Blue Apron for a while and got an unreasonable amount of salmon for some reason. It's been almost 6 years and I can still barely eat salmon after that. So I can definitely understand where the prisoners were coming from on this one.
Things might have changed since then, but from what I recall while we had some options on what to pick, for example I could eliminate red meat entirely, there was no option to get meat and not get salmon. So pretty much every week at least one of the meals was salmon.