I was able to find answer to this on another blog. Signature service is special service for high-end appliances (whatever that means) wherein you get things like service tech coming to your house for installation or the like. I don't think it's something I will miss, as I never heard of it anyway. I was worried I was losing something on my "smart" TV that I paid extra in the price tag to get, but this sounds like an outside service that really isn't necessary for day-to-day operations.