I was kidding!
Replica watches are not illegal here in the US. That's like taking your Shelby Cobra kit car into a Ford dealership for an oil change and them keeping the car.
I've heard the theory that at a Rolex AD they could try to confiscate it, but I still find that a stretch. Your watch is your property..they can't take it from you.
He might refuse to work on it is more likely because he might have a parts account or a moral problem.
If your really concerned, just tell him you have a high quality replica watch. If he has a problem and you need your bracelet fixed, find a small jeweler.