Apple is really starting to clamp down on iPhone repairs not carried out by an authorized technician. Back in August, unofficial batteries were flagged as requiring a service, now unofficial iPhone displays are being targeted.
As Engadget reports, a new Apple support page has appeared entitled "About genuine iPhone displays." It explains how important using a genuine Apple display is on your iPhone and that any repairs should be carried out by a certified technician. Apparently not doing so can lead to a series of problems including multi-touch not working properly, touches registering unexpectedly, the display not turning off during calls, unintentional battery drain, brightness problems, and the list goes on.
Apple clearly doesn't want you opting for an unofficial repair and has gone so far as to display a message on all iPhone 11 models running iOS 13.1 if an unofficial display is detected. If you navigate to Settings > General > About on an iPhone 11, iPhone 11 Pro, or iPhone 11 Pro Max with an unofficial display fitted, the message "Important Display Message - Unable to verify this iPhone has a genuine Apple display" will be visible.
It's also made clear on the support page that the message doesn't "affect your ability to use your iPhone or your display." However, the message will be displayed for the first four days on your lock screen and then in the Settings app for 15 days after which point it will only appear on the About page.
Apple is not doing anything wrong here, but clearly it's hoping users who have an unofficial display fitted will see the message and pay (again) to have a genuine display instead. I doubt that's going to happen very often.
The repair options have opened up recently for Apple devices, but they are still tightly controlled by Apple. 1,000 Best Buy stores now offer official repairs and Apple is allowing independent iPhone repairs, but there are a few caveats.