@Meowmix yup I understand that AC+ is tied to the specific device serial number/IMEI and it makes sense that the 2 years start fresh when upgrading and opting for AC+.
I want AC+ on all my current iPhones so I guess there's nothing really to do on my part as the coverage will deactivate on the old phone and activate on the new (current) phone (and restart the 2 year period) pretty much automatically.
Also @Meowmix have you always received email confirmation from Apple when AC+ was activated on a new device (using AC+ monthly from either Rogers or Telus)?
AC+ is active on my gf's iPhone X. It's been active since a couple days before we received the device which is excellent. But she has yet to receive the email from Apple. Probably doesn't matter much as I can see the coverage start and end date as well as the AC+ certificate number online. But an email with the documents would be nice for information purposes.