I haven’t had my battery changed but I still got the notification
My iPhone 12 sent a notification about my batter not being a genuine apple batter but I’ve never had it replaced.
iPhone 12, iOS 14
Question marked as
Hi, did you purchase your iPhone new from Apple ? If so make a Genius Bar appointment. If you bought it from a third party seller it could be that they have changed the battery. Depending on your region this is Apple’s United Kingdom Support Page for iPhone Repair https://support.apple.com/en-gb/iphone/repair/service to use as a guide.