I would say update both devices. Do a manual backup on 14 PM after either using iCloud or (encrypted backup for health data) Finder. Restore the backup on 15 PM.questions.
I haven’t updated my iPhone 14PM to iOS 17.0.1
- should I update my current phone first before transferring stuff on the new iPhone?
or
- should I do the restore from iCloud back up first, then update the new iPhone to iOS 17.0.2?
if I update my 14PM to iOS 17.0.1 now, should I update the 15PM first to 17.0.2 before restore?
I just need to avoid some failure that could occur while setting up the phone.
I normally just set up as new after backing up the old device through iCloud then signing in to resync all the data back but only install the apps I need as a fresh start.