I don't think it's cooking unless you are applying heat to cause a chemical reaction. So, making a grilled cheese sandwich counts as cooking, but a BP&J does not.
Some of the constituent ingredients have to be cooked, but ceviches and sushi rolls aren't cooked any more than salads or burritos. They're assembled or prepared.
You could cook using an exothermic reaction between ingredients, but I don't think that's what's happening when making ceviche, so a ceviche is not cooked.
Ceviche is said to be "cooked" with acid, even if that's not the most accurate term. And most forms of sushi are made with cooked rice, at minimum, and not uncommonly with other cooked ingredients. So those things kind of muddy the waters for your point. But a clearer example may be something like beef tartare, a garden salad with a vinegarette, or sashimi. Those things are "prepared", not cooked, because no cooking is involved in their making. Cooking is specifically the preparation of food utilizing heat. Chefs prepare plenty of dishes that do not involve the act of cooking.