Ah, but yes they can! I found this out when I had 5 pounds of mushrooms left over from an event a group had at our American Legion. I did some checking on the internet and gave it a try. You can saute them in butter or olive oil, then cool and freeze them. I was not convinced until I thawed out a quart package several months later, added some Worcestershire sauce and some garlic and used them to make mushroom swiss burgers. They were perfect.
Now if you breaded and deep fried them, then no. But sautéing in butter or olive oil works great. Who knew!