I don't think there is a right or wrong here. If you identify with your Dalish character, or for whatever reason with that story you've found there, then certainly Sera didn't "learn" anything at the temple, in the sense that she didn't come around to your strongly held beliefs. Which can be confusing and frustrating and mystifying.
If on the other hand, you feel as I did about the whole thing, then there was nothing for Sera to "learn" at the temple. Her fears and suspicions about magic seemed pretty well justified. From that perspective, Sera suddenly believing, or feeling a stronger connection to that culture, could be perceived as horrifying as a lover suddenly adopting a belief system that you find wrong, dangerous, or even delusional.
What seems a frustrating lack of change or evolution to one person might be a reliable stability to another. As Sera says to me at the end, "You still you, yeah?"
For me, Sera did change, but those changes had nothing to do with mythal or dalish beliefs, and more to do with finding a home, discovering hope and acceptance and friendship. And yeah, she's pretty low on empathy while needing it desperately, and that contradiction is very interesting to me. Yet she opens up slightly. When she gave me a gift, it felt as if she'd never done that before, never given to one person, and she was kind of uncomfortable and embarrassed about it.
The gift she appreciated, the gift she loved, was not Vivienne's suggestion, but the fact that I announced to THE ENTIRE WORLD that we were together and I wanted to give her something. She didn't expect to give a gift, and she never expected to get one either. She was kind of surprised and goofy about one, and delighted about the other. But that was the perspective from my two Seramancers.
I don't think either perspective is right or wrong. It's who your character is, who you are, how you've moved through the story, and what moved you. What you expected, and what felt right or wrong about the outcome.
(this is all my stupidly rambly whatever before bed, probably doesn't make sense)