Dealer Technical Bulletins (DTB's) as we refer to them at the dealer are done when a customer complaint is documented, and a relevant DTB exists. They're not done automatically. That's what Service Campaigns/Recalls are for.

The privacy issue the dealer is referring to concern personal customer information. There's no reason they can't give you a yes or no answer as to whether or not a specific repair has been performed. Offer to give them the VIN, and ask if they can check when they get a chance.

BTW, which DYB are you referring to?