Interesting. How did you freeze the beans? I have been buying four each, 12 once bags, putting three in gallon freezer bags, squeezing out as much air as possible, and have not noticed any difference from the freshly roasted bag. It takes about a month to go through the 4 bags so they aren't in the freezer that long. If I was to freeze the unopened 12 once bags for a longer period I would vacuum seal them in a bag before freezing.
Based on what I have learned about freezing in vacuum sealed canning jars, they will last as long as needed without degrading. I am resting the beans to within a few days short of the roasters recommendation before freezing.