(1/2) I gotta admit I thought Touch the sky it was Weiss's. Because Atlas, and honestly anything with mirror in the lyrics kinda makes me do the connection XD But also, it always sounded not exactly right? Like the mood was “I’m past this” and she was still in conflict. Which made me think it was for everyone? Like, going back to that feeling in Beacon, having overcome the difficulties in getting there and being in the “new normal”. But still, it felt like more, but couldn't pinpoint what it was
I can definitely understand the Weiss hang-up, because mirrors have always been associated with her lyrics, BUT... the context for this song lives in the buildup right before it appears in the show.
With this shot. Literally happening about ten seconds before Touch the Sky starts playing for the first time, with the first lyric that you hear being "I looked in the mirror".
You're right that for Weiss, it wouldn't be well-timed. She's still extremely unsure about being in Atlas, and that doesn't change until the middle of the next episode when she tells off her father. But for Blake, without the constant threat of Adam anymore, this is suddenly the freest she's been in a very long time.
Touch the Sky is about Blake.