I think these guidelines must be for freezers attached to fridges that don't get too much colder than freezing, for items in store packaging. I have two full-size, frost-free upright freezers that are kept at or below 0 degrees. I use vacuum seal bags, Tupperware intended for the freezer, and in some cases like freezer jam and pesto, glass jars. Kept at zero or below, and in airtight/vacuum sealed packaging foods will keep much longer than these guidelines. There is a possibility of textural degradation over time, depending on the food and packaging, especially prepared foods and fruits and vegetables that by their lumpy nature have some air in the packaging, but as long as the food has been kept frozen it should be safe to eat. If I run across veggies in the freezer that have freezer burn I use them in my next batch of stock - fruit ends up in sorbet. After removing all the store packaging, I vacuum seal all my meat heading to the freezer, and it does not get freezer burn. I have used it, with no noticeable difference in texture/taste, after it's been frozen 3 to 4 times longer than these guidelines. I garden, and have learned that I can grow things that hog space like tomatillos and basil every other year, prepare and freeze the harvest and it will keep until the next harvest of that crop, two years on. Carefully prepping food headed to the freezer and maintaining a very low freezer temperature makes all the difference.
I think these guidelines must be for freezers attached to fridges that don't get too much colder than freezing, for items in store packaging. I have two full-size, frost-free upright freezers that are kept at or below 0 degrees. I use vacuum seal bags, Tupperware intended for the freezer, and in some cases like freezer jam and pesto, glass jars. Kept at zero or below, and in airtight/vacuum sealed packaging foods will keep much longer than these guidelines. There is a possibility of textural degradation over time, depending on the food and packaging, especially prepared foods and fruits and vegetables that by their lumpy nature have some air in the packaging, but as long as the food has been kept frozen it should be safe to eat. If I run across veggies in the freezer that have freezer burn I use them in my next batch of stock - fruit ends up in sorbet. After removing all the store packaging, I vacuum seal all my meat heading to the freezer, and it does not get freezer burn. I have used it, with no noticeable difference in texture/taste, after it's been frozen 3 to 4 times longer than these guidelines. I garden, and have learned that I can grow things that hog space like tomatillos and basil every other year, prepare and freeze the harvest and it will keep until the next harvest of that crop, two years on. Carefully prepping food headed to the freezer and maintaining a very low freezer temperature makes all the difference.