The free year seems to be tied to the purchasing ID, not the activating ID of the new device. I bought an iPhone XR for my daughter's birthday last month which was set up and activated using her Apple ID, but it's me who's got the 1-year free trial.
I'm not sure how that works though if you bought the qualifying device from a third-party, or if you bought it from a bricks-and-mortar Apple Store so the purchase wouldn't be tied to a specific Apple ID - I guess then it must be tied to the ID used to activate the device which seems a very inconsistent approach!
What's other people's experience here?
i have the same issue. I bought an iPhone 11 for my sister and I am getting the free trial option. I bought it from an Apple store and provided my Apple ID so you are right. It’s tied to the purchaser which is weird. She is also in my family for Apple Music subscription so I can share TV with her as well.