Personally, I can't stand this warm "yellowish" screen. It looks like I am using a smoker's device.
Within a certain colour temperature range the eye will automatically compensate. In other words, we have a built-in auto white balance. This is there because white does and will look different under different lighting conditions, including ones that exist in nature. So just like a camera needs white balance controls, so do our own eyes, and nature has provided us with an auto white balance for this purpose (for example a cloudy vs a sunny day). However, there are 4 key things that can make this fail
1) The white is so far away from white, that the brain does not see it as white anymore. Then it will look yellow, or pink or whatever colour the screen is strongly biased towards
2) The screen is not uniform in terms of colour. If part of the screen is bluer and part is redder, then your brain will select one part as being "white", typically the bluer part, and the rest as being yellow or red etc
3) If you have a TV, or phone screen nearby with a different colour temperature for white, the brain will choose one of them to be "white", typically the bluer one, making the other look tinted. However if that "tinted" screen is seen without any other for comparison it will appear white.
4) A display emits light but also reflects some light from the room. Depending on the light bulbs colour temperature from the light in the room, it can modify the colour temperature of what we see. For example a warmer room lighting, will make the screen seem more blue. A photography editing monitor typically comes with a hood to help shield it from the influences of room lighting.
When we talk about a warm or cool display, we are talking about a scale that runs between red and blue. That is to say, when we talk about a colour temperature of 7000k, we are talking about a bias towards blue. And when we talk about a colour temperature of 6000k, we are talking about a bias towards red. You will of course know, that yellow is not the product of blue and red, but red and green. So in a display that is spot-on with red and blue levels but has a bias on green, it may look yellow, but it will be wrong to say it is warm...it is simply wrong!
6500k is the agreed standard that displays used for photos and video. 6500k or the almost identical but slightly better definition D65, refers to the colour temperature of natural sunlight. It should be emphasised that this will not and should not yield a white that looks like something from a commercial for laundry detergent. A lot of people do like a very blue white because it looks more pure, but it is not correct. Take a sheet of paper and take it outside on a sunny day..and you will notice that it does not look like the white from a detergent commercial. Take a photo of people outdoors with a camera set to the right white balance and take a mental note of how the scene looks in reality with skin tones. Look on it with a monitor set to D65 and you will feel like you stepped back into the photo.....on a blue screen, notice how all the skin tones have changed.
Bottom line is that every iPad pro or display is different. I have found through experimentation that the yellow bias is often linked to how tight the screen is under pressure in its casing...for example on some iPad pros, by pressing firmly (not too firmly) on parts of the screen it goes a bit yellow. So as every display varies, it is simply a case of whether the level of tint is within your brain threshold to auto-correct. But also consider that if you want accurate, think about how a piece of paper looks on a natural sunny day, and not the white t-shirt on the detergent commercial.