The key here is “satisfaction.” Satisfaction is not an objective measure of sexual function. For some perspective, women have rated their partners’ orgasms as more important their sexual satisfaction than their own. Women have also reported that emotional, subjective factors such as body image and relationship status play a larger role in satisfaction than objective measures of physiologic function. This is one pattern I find immensely frustrating, as I seem to be at odds with the values of my gender.
You have to consider that most of the women who choose to have these surgeries have insecurities that are interfering with their ability to enjoy sex at all. They may feel so self conscious, they can’t relax with their partners. They may also not feel comfortable receiving oral because they are so ashamed about what they look like.
So on one hand you have women who have had labiaplasties performed by highly experienced experts (not representative of the average standard of care) reporting improved sexual function. But this should be expected given the psychological distress prior to surgery. Other factors such as cognitive dissonance and the placebo effect come into play.
On the other hand, you have studies showing that women with larger labia minora actually report more pleasure during sex and lower rates or sexual dysfunction. This would make sense considering they have more sensitive tissue that helps aid in indirect stimulation of the clitoris during intercourse.
It is most important to note, that when it comes to female genital cosmetic surgeries, there are no training standards. Most doctors doing these are self-trained, which is dangerous. Neither plastic surgeons nor OB/GYNs are trained during residency or educated in the surgical anatomy involved. The distal course of the dorsal nerve of the clitoris is notably not mentioned anywhere in peer-reviewed literature on techniques. Detailed surgical anatomy and physiologic function simply are not covered to the extent they are with other surgeries. It is almost as if vulvas are approached as inanimate objects rather than functional body parts. This pattern is pervasive throughout the literature.