I don't think this is correct, wood or fish weren't announced to spoil over time. And although you could freeze fish ( animal product & food) it make no sense to me to put some wood in the freezer ^^ ( plant & not food ).
Plus i am not convinced a hidden random freshness is a good idea. To me it serve no other purpose than defeating the purpose of the spoilage mechanic in the first place. I think it is like opening a window to get cool air, while at the some time cranking up the heat, to have hot air. Introducing the whole mechanic just for people to instead use freezer like they could use current mod that put item in box seem very counterproductive, there will already be the "stacking on belt" mechanic that serve this purpose.