The only question is how much extra water from processing the product gains during the freezing process or how much water might evaporate from the product if it is fresh.
There could have been a slight water gain in the older freezing processes, which weren’t as cold and so took longer. Today’s flash freezing should pretty much eliminate that.
I doubt that most products would lose much water by the time they get to you, although it’s a possibility for a few fruits.
Hard to imagine chicken being affected either way. I’d think that any weight differences would be negligible, even if you let it freeze in a home refrigerator and then thawed it out. It’s too impermeable.