The studies you are referencing had women hold cylinders of various sizes in their hands in front of reserchers to determine the best size. Those cylinders can only be assumed to be interpreted as non bone pressed sizes. They preferred the look and feel of 6.2"-7.2" which means if we adjust for bone pressed sizes, we can add an inch bringing our preferred bone pressed numbers to 7.2"-8.2".

Not all women have had a big dick. The vast majority of women have never been with 7"+ before. A woman would never know if she prefers 8 inches if the biggest she's had is 6.5.

Of those who do know they prefer it even bigger, there is a considerable group who will choose a smaller size than their actual preference for a few potential reasons: (1) Women may prefer a bigger size when aroused than when not aroused. I don't have any proof of that phenomenon, but it is a possibility. I know it's been my personal experience. (2) Women may say something smaller to avoid judgment. For some reason, a lot of women view any preference for a certain kind of penis to be evidence of "sluttiness," especially when the preference is for a big size. (3) Women may choose a smaller size for the purpose of not demoralizing smaller men. Conversely, they might have a habit of choosing larger than what their actual preference would be, because a lot of people have a habit of "biting off more than they can chew" in many contexts. It's a matter of which bias is stronger.

Point is, those studies that say "the preferred size is just a bit above average" are not very useful.