Guys there is no "Yellowgate" on the new iPhones, in fact, what you perceive as "yellow" when viewed next to an iPhone 6/6s is in fact the correct White Point.
The displays on the 6/6s only use the sRGB Color Gamut and have a "blueish white point" with a color temperature of 7300K as measured by DisplayMate (
http://www.displaymate.com/iPhone6_ShootOut.htm)
But with the new DCI-P3 color standard for the new iPhone 7 the white point is now the correct D65 white point at x=0.3127 y=0.3290 with a color temperature of around 6500K.
So basically what you say is a "Yellowgate" is in fact a "Bluegate" from your iPhone 6 and 6s with a blueish white point. What you see now on the iPhone7 is the correct white point, as in how white should actually look like on displays.
(Check those links for more:
http://www.displaymate.com/Display_Color_Gamuts_1.htm
https://en.wikipedia.org/wiki/DCI-P3
https://en.wikipedia.org/wiki/Illuminant_D65 )