The big problem with cis is the assumption that everyone has a gender identity. There are many people myself included that do not have an innate sense of gender. Gender is something separate from me that is imposed on me by society. It is external not internal.

I agree with her that it doesn't make sense for the vast majority of people to live on the extreme end of the masculine or feminine spectrum in their culture, most of us fall in between those two extremes, but the in between is not transness or nonbinary it's just your personality. Pressure to conform to sex stereotypes definitely exists, but it is not necessarily trauma when people conform. Much of the time it is a matter of habit and convenience. In homophobic societies homosexual people who attempt to engage in heterosexual relationships may very well have some trauma involved. (This also includes homophobic subcultures where gay men and lesbian women are pressured to overcome their "genital preference" to be open to dating someone of the opposite sex.) Heterosexual people will not have trauma involved at all, because going with the cultural flow is well, easy.