Did you experience IRROPS en route to Rome? Occasionally I have been protected on a later flight, taken the earlier one, and received an upgrade notice pertaining to the later flight after disembarking from the earlier one. Similarly, I have been auto-rebooked on one routing, found it unsatisfactory and changed it, and continued to receive notices pertaining to the itinerary as originally rebooked.

I assume if there was another passenger's name or other identifying information, you would've said so. Strange.