By not telling you may be risking your own life not to mention the lives of sick people who are in the hospital. Most people in the hospital already have compromised immune function and then you come along and expose them to something, possibly strep.
And......if you're having general anesthesia the doctor will see your sore throat and most likely cancel the surgery. And.....everyone will be upset with you for not telling them ahead of time. You'll have gone thru being admitted, prepped and be in the operating room when they cancel the surgery because your throat is red. It's possible that you'll be charged for that part of the surgery and that your insurance won't pay because you didn't follow the rules.
Please follow the rules. They are in place for a reason and that is to protect your health and the health of other patients. And, calling two days in advance allows the surgeon to schedule another patient in your place. You cannot get rid of a cold/sore throat in 2 days.
Call your surgeon and let him know you have a sore throat. Let him decide if it's safe for you to have surgery. And let him help some other patient. If you go in with a sore throat and they cancel surgery at the last minute you have wasted the time of several professionals and the operating room.
Geez! Your surgery is elective plastic surgery. It will not make a difference if you reschedule.