I noticed that, too. The trailer tricks you into thinking Rhiannon’s is going to be (or at least discover that she is) bi, but upon rewatching the trailer after seeing the film, you realize there’s only the one girl during the montage of kisses. The film even specifically sets up that almost all the romance occurs when A is male, the silent implication being that Rhiannon’s straight, so she can only interact physically with A when they’re in a male body.
A, set up as Rhiannon’s soul mate in a particularly on-the-nose way, even decides that a great match for her just happens to be the generic tall, white boy who is suitably the 16-year-old version of deep for having inspiration quotes on his wall.
They barely delved into Rhiannon’s inevitable reputation as a slut for being seen with a handful of different guys in the days after she broke up with Justin. She ought to have been making eyes at girls half the time, a missed opportunity to address the myth of bisexual promiscuity.
In fact, so much time is devoted to A and Rhiannon’s romance that literally every other relationship of Rhiannon’s that the film makes you believe is going to be repaired with A’s help are left unresolved or resolved with little attention:
Her older sister’s reckless behavior
Her father’s untreated bipolar disorder
Her mother’s infidelity and martyr complex
The neglected friendship with her best friend
Does Rhiannon skip school a half a dozen times during her relationship with A? It seems like it.
In fact, you can tell they strained to tell the story properly by making it a teen romance when making Rhiannon and A college students or young adults would fix a lot of plot holes, including how Rhiannon has so much free time, so much independence from her family, and the social maturity to address the implications of their relationship. Not to mention filmmakers are slightly more comfortable exploring a character’s evolving sexual orientation when they’re 18-25 rather than 16.
That whole sequence of their hypothetical future seemed like an even more interesting and heartbreaking movie. Like, why make 17 Again when you could make The Time Traveler’s Wife?