I guess it's a testament to the loving subtleness of introducing the theme.
It's particularly moderate here because it deals with merely the rigid teenage roles enforced through peer pressure. It's a bit like an antithesis to Rainbow Dash, I guess, who is authentically (well, more or less) tomboyish. Although we could also discuss what in society made her be afraid of being known to like reading books. That must also be a story about peer pressure. She'll have spent a lot of time with flyers and they probably imposed that stereotype complex on her.

Also, the fact that I am re-watching season 8 episode 22 after having made a note to rewatch ages ago is a testament to my burnout.
Then again, maybe it was the perfect time for it. (But if perfect timing was entering my life, I think I would notice.)