Identifying users with a new mobile device

Hey everyone - I’m trying to build a cohort for users that have recently upgraded their mobile phone so that I can message them with steps to keep them in a happy state. For example, I’m looking for users who recently got a shiny new iPhone 15 (or whatever). I’ve tried building a cohort with the “distinct value” for device type. And I’ve also tried building a segment using offsets, but in both cases I’m unable to eliminate the tricky scenario where users have multiple devices that they are going back and forth on (or perhaps multiple users sharing credentials). Appreciate any suggestions / guidance from the experts here!