Most freezers already do a defrost cycle so could probably play with that. It’s only a few degrees oscillation so idk how much savings you could get there.
A modern fridge only consumes around 350kW a year or so, so any savings are going to be modest. It would not be the first target if I wanted to cut my power usage, especially if the consequence was going to be more freezer burn.
I think the consequence would be less freezer burn and more frost buildup.