LMSC A paper published in Nature in 2016. It finds beans ground from cold is better than at room temperature; but, this finding is related to beans stored in liquid nitrogen and ice. There isn’t anything on the frozen beans. Another caveat is the experiment is done just on 4 bags of beans making the outcome statistically unreliable in IMHO.
I remember this from years ago and instead of cold beans being harder to grind, in many cases they were more brittle, although I’m not sure this holds true for very light roasted beans.
My primary concern with anything that comes out of the freezer is condensation/smells…if it’s been completely sealed and then allowed to come up to temperature before opening, then it should be OK..but I’m not 100% sure. I am 100% sure opening the back whilst frozen can cause moisture to condense onto the beans and I assume thaty’s not going to be fantastic for the grinder?
My secondary concerns are around freezing oils and fats altering their structure in the coffee, the effect on volatiles and very cold coffee in the portafilter.