Tbsrider is correct on all points. You don't say where you are, but I'd be greatly surprised to hear any Triumph dealer anywhere in the world claim to have not heard of this happening before. They should have contacted the factory or the importer for your region, in any case, before undertaking such a repair at the owner's expense. Their seeming lack of awareness would be a greater worry to me than the fairly low risk of encountering the mechanical problem itself.
And just for the sake of accuracy, you don't have a 2004 Rocket 3.
1. Although there were a small number of early production units titled as 2004 models, mainly in the UK, most of the ones built that year are designated as 2005 models. In most of the world, the tenth character of the VIN should be a digit signifying your model year, if you wish to double check.
2. Even if yours is titled as a 2004, it's still not a Rocket 3. Those haven't been made for three decades. The Rocket 3 was a BSA. Triumph makes the Rocket III
And, I have no idea who would make the supposed Rocket 111 we see mentioned so often. Can you imagine the labor bill for checking valve clearances on a hundred and eleven tiny little cylinders?