I have never heard of anyone freezing soaps. If the soaps are not open yet then there should not be a problem with how long they will last. And if they are open, will keeping the covered and stored properly not make them last long?
Why freeze?? People buying all the time vintage soaps from the 40 and 50's....I do not see the need to freeze. I just pack it well in a tight closing plastic bag, and store in the dark, in my basement.
The only reason I could ever see to freeze a (glycerin-based) soap would be if you wanted to pop it out of its tub & put it in another container. Otherwise there's no point. I have decades-old soaps that are just fine.
I may have been responsible for the OP's question since minutes before his post I mentioned in the French soaps thread that I had some Provence Sante and some Pre de Provence in the freezer awaiting future use. Mostly, I just had room back in the far corner under a wire rack so it was convenience as much as anything else.
That being said, and those are the only soaps I have ever put in any kind of cold storage, they all contain shea butter. I have read elsewhere that shea butter actually can get a little rancid. The shea butter I read about was a much purer body rub product than the consistency that ends up in triple milled soaps and the like. Something from that article possessed me to stick them in the freezer. Probably unnecessary, but they're fine. When I get ready to shave with them and get them thawed out, I'll give a full report here in the soaps forum.
If I ever (it's not in the cards) bought one of those full kilogram bricks of Cella, because of the lack of preservatives, I would definitely be cutting it up into six separate bricks and freeze wrapping and freezing the sections not in use. Would I need to? Doesn't matter. I'd rather err on the side of protecting my investment.
I once froze Cella to pop it out of the red tub, but it seemed to cause some seperation, kind of like little blobs of fat.
But it didn't affect the performance.