I've had a look at the Iceland website, but I can't see anything that says yes or no to defrosting them.
I would imagine that they wouldn't completely defrost in just a few hours in a fridge anyway, so they would be mostly frozen still when you come to eat them. That's assuming you take it from your freezer at home on the day you plan to eat it. And the cooking times will be for the meal being frozen.
Just make sure that they're completed cooked through before eating
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