One aspect that is interesting in the film is the role of masculinity and femininity. While the girl was two mothers, it is clear one ("play sports!") is the masculine figure and one that wishes to talk is the feminine one. Also, the notion that gay women would play sports and gay men would be in drama. So, I think it shows how hard wired certain gender roles are established that even when you "switch" things you have these conditioning factors at play.
The message is simple though, misunderstood minorities are ostracized from their communities and even their families. You can see all sorts of pocket communities of this where people are disassociated or bullied because they are some sort of "other". The argument of wishing for greater understanding to reduce ignorance and hate is a fine message.