Your comment on the extent of oiling off of the Swiss cheese prompted me to review what I said in my last post, where I saw that I had the order of the Swiss cheese and cheddar cheese reversed in relation to the extent of oiling off. I have now corrected that post to indicate that the cheddar cheese had the most oiling off of the three cheeses. Thank you for your comments that made me go back to my last post.
I don't work with cheeses to anywhere the degree that you do but cheeses do lose moisture with time, and especially if left uncovered at room temperature or exposed to drying room temperatures often enough. As a simple example, when I was shredding the different cheeses, there were some straggler shreds that ended up on my work surface and went unnoticed. Later, as I was cleaning up, I saw those straggler shreds and noticed that they had become brittle and would break into small fragments. All three of the cheeses I used were firm and had the same general appearance and texture, even when shredding. However, I am sure that there are a lot of variations from brand to brand and I know from reports I have read that some cheeses often do not comply with federal regulations that govern the permitted water content. The concern is that producers do not load up their products with water in order to maximize profits.
Since you mentioned the whole-milk mozzarella cheese, I went to the nutritiondata.self. com website and calculated the water content of a generic whole-milk low moisture mozzarella cheese. It is 47.3%. For a generic whole-milk mozzarella cheese with higher water content, the amount of water is 50%.