To a certain extent I do think that having a form of gender conformity can help reinforce attraction. I think in a number of ways this can be appealing to a number of people who may be looking for someone with more traditional values and may help both sexes in a way.
As much as you can choose to do whatever you want, you can't choose your tastes. You either like peas or you don't. Same with gender attraction and any other taste you can think of. As such, you can't just group people in a certain way to encourage the kind of attraction they will have.
Gay people still exist, even in hyper masculine/ hyper feminine environments.
Gender conformity is a tool of oppression used to emphasize differences in people in order to integrate a sense of superiority to people with certain parts. It has also been used to sexually oppress certain members of society. There isn't really anything attractive about it, unless you have some sort of fetish for it.
All that gender conformity reinforces is stereotypes. Besides which, why would we necessary think that attraction between sexes is something that we should or should not reinforce? People are far too concerned with who is attracted to who and who conforms to their own gender stereotypes. Neither of these issues has an impact on the rest of society.