Why wouldn't you pick the time when the public would be convinced a price rise is justifiable in order to raise prices (on a fairly inelastic good?) That isn't what you need a conspiracy for; the biggest would just press release that they were doing it, and the rest would follow. You might need a conspiracy to keep smaller producers from defecting from the price the biggest are setting, but the defectors wouldn't actually have the capacity to replace the price fixers, so they'd just be setting money on fire by not following.
I think it's pretty clear that they do explicitly discuss fixing prices with each other, but there's no actual need to do that.
Notice how that's not a story about price-fixing of a commodity but of a (delicious) intermediate industrial product destined for ultra-sophisticated buyers. There's no story about people price-fixing potatoes.
Also notice how the prices don't move up and down with incidents of potato blight or whatever.
Further: for this to be explanatory, you have to show why, after HPAI outbreaks subside... prices come back down.
When companies work together to set prices they can lower them a little sometimes (while still increasing their profits) and ruthlessly gouge the hell of out consumers the rest of the time hopefully without raising too much suspicion.
I think it's pretty clear that they do explicitly discuss fixing prices with each other, but there's no actual need to do that.
https://farmaction.us/wp-content/uploads/2023/01/Farm-Action...
edit: also, check out frozen potatoes https://jacobin.com/2025/01/french-fry-price-fixing-antitrus...