>>21432234 (OP)>Would using a butter that is 2 months out of date but was frozen the entire time to bake apple pie a bad idea?Maybe.
(1) it will pick up that nasty "refrigerator odor" and make whatever it's put in taste like crap, and
(2) even in the freezer, butter can still develop mold internally.
I used to freeze butter for a long time because I didn't use it much, and both of these were problems. I'd take out a stick that had never been unwrapped, let it thaw for a few minutes, break it in half, and find a huge vein of black mold inside it.
Not to mention that it still oxidizes (unless you have some sort of oxygen-proof container for it with oxygen absorbers inside) and so the outside gets those hard yellow rancid bits.