Acalculi cholecystitis (cholecystitis not caused by gallstones) is rarely treated with surgery, it is usually just antibiotics. Cholecystectomies are indicated in cholecystitis, gallbladder tumours and gallbladder perforations (rare).
Is it possible that these people already had asymptomatic gallstones and whatever was in this food triggered a gallbladder attack?
While certain foods (high fat content) can trigger biliary colic, I’m not aware of any specific foods that would trigger this more than any other with a similar fat content