Good question. We have a debate about that in my house.
My husband insists that the canned cat food from the fridge is taken out and brought to room temperature before feeding time. His theory is that, in the wild, prey is most often live and warm (of course, the exception would be fish.)
I'm not sure it's so important but we do have one cat with a long-ago broken tooth, so it may be more palatable for her if it's not ice cold.
Also, I have found that warming food in the microwave can induce a sick cat to eat because, according to the vet, cat's rely heavily on scent for attraction to food.
Tuna is readily accepted by our felines, warm or cold, maybe because it has a strong scent in either case.
So, you see, you are not the only one over-thinking this. lol