Never seen that mentioned in the winter ops brief. On contaminated taxi ways we are told not to deploy flaps during taxi out until reaching the runway, and leave them out until inspected on taxi in, owing to the possibility of slush getting thrown up into the tracks and mechanism.
As you say, it is reasonable to inhibit flaps on the ground with a cargo door open, because in that instance there will be ramp personnel around and you don’t want to clobber them by moving the flaps. But I can’t see what relevance that has to winter ops specifically?