I think this recall is for the rear caliper mounting bracket bolt. Its the bolt that mounts the bracket to the swingarm, not the two bolts that mount the caliper to the bracket. I believe this bolt replacement requires partial disassembly of the rear hub. Check page 335 of the manual. I think there was an incident where a couple of these bolts sheared, allowing the rear caliper to rotate on a few bikes. Seems a batch of the bolts were improperly tempered. Triumph decided to replace all bolts from that batch, as a failure could result in a crash.
If they need you to bring the bike in the verify the VIN and that the recall hasn't been done, fine. No dealer should have to keep your bike until the replacement part comes in, unless they feel it would open them up to liability if the part fails while the replacement is on order.
I know mine was done during pre-delivery check (bought mine in October, 2006)