Update:
I was able to go to a different Apple store that was 5 minutes away from a doctor's office I visited today. Although they let me into the store, there were more strict guidelines and I was assigned a sales person who escorted to one of the product display tables. As such, I only had access to 2 iPhone Pro models. Both floor models were worse than mine: they were warmer than my unit and achieved a lower maximum brightness than mine. Same settings (auto-brightness off, True Tone off, night shift off). I also looked at 2 iPhone 12s (non Pro) and both were warmer. And as expected, the Pro achieved a higher max brightness than the non Pro.
There is a patently obvious difference in these iPhone 12 displays, when compared to the previous OLED iPhones. Could be the change in calibration to make it warmer or it could be an issue with 99.999% of the initial batch, at this point, I don't care anymore. There is a slim chance of getting a better unit at the moment. Unlike previous years, at least mine is uniform and don't see much color shift (if any) when looking at an angle. Blacks look amazing (as expected), and no issues with the gray. It just the damn yellow hue.
After having visited 2 different stores and checking at least 5-6 different Pro display units (and 3-4 non Pro), all worse than mine, I've decided not to return mine and re-purchase, as the odds of getting the same display or worse, are likely 99.9999%, if not 100%. Had I seen at least just 1 good display, I would be willing to go through the hassle of trying again. I made the mistake of selling my previous iPhone therefore I cannot just return and wait a month or two. I'll just need to get used to this warmer screen. If by any chance I start to see cooler displays in a couple of months, I'll try to have mine replaced via warranty.