Honestly i think it's the same old story for a long time… i joined the panel lottery since I bought an iphone x having bad experience. This year i decided to upgrade to 13PM and although i was happy at the beginning i started to notice a bad uniformity of the display with 1/3 of the panel which has a pink tint compared to the other 2/3 which is very annoying... in this thread some time ago i noticed a post where reference was made to the serial numbers of the display but this thing was only talked about on the iphone 12 series due to the too yellow screens.
Last year we had two samsung and lg suppliers, who supplied apple with these serial numbers and from what I was able to learn:
G9N (good quality samsung panel)
GVC (good quality lg panel)
G9P (low quality samsung panel)
GH (poor quality lg panel)
the strange thing I noticed though is that the iphone x, xs, 11 pro, and even 13 series are also subject to this display classification.
From what i could see the few G9N displays that i had in my hands were much more beautiful than others that had yellow tints, pink tints, bad uniformity, etc... strangely in fact my iphone 13PM has the display that starts with G9P but it is much better than the crap I've seen in those years.
I think apple is aware of this but keeps buying panels A and B to maximize its profit, because in the end most users don't notice it.
To check the serial number of the panel just do a sysdiagnose: press simultaneously vol +, vol-, power and release immediately, the iphone should vibrate. Then go to the analysis data and search for sysdiagnose. Export to file and unzip the archive, open pages and look for the iodevicetree file in the ioreg folder, once opened find this word: raw-panel-serial-number.