Okay, three things I want to say here.
1. I have a very experienced friend who was having trouble with a thread that was constantly breaking. She finally called the thread manufacturer who instructed her to place the thread in the freezer overnight. She did and it worked great after that. Nobody knows why.
2. Freezers do not rehydrate anything, especially if they are "frost free" - they do the opposite! A frost free freezer removes moisture from the air inside the freezer. This prevents it from collecting on surfaces inside the freezer and turning into frost. It also removes moisture from your food, which is the cause of freezer burn.
3. Sharon Schamber will actually dip a cone of thread into white mineral oil, let it drain on a paper towel, then use it in her machine. She agrees with the point that sometimes thread gets dried out and needs to be re-moisturized. This topic has been discussed on this board before, and there will be nay-sayers who will refuse to try this because they're afraid of getting oil on the quilt. I've never seen any oil spots on any of the award-winning quilts that Sharon makes.
My point is it can't hurt to try. Try the thread in the freezer; if it works, great! Try the oil on the thread, and if you're nervous about oil stains, then put some of the thread on a bobbin, oil it, and try it out on scraps.