Sora and Sky aren't the same thing exactly in Japanese... It's only when Sora's name is written in Kanji or whatever, does it mean the same thing.Sora and sky being the same thing in Japanese (I know stating the obvious), it seems like wordplay to me. Looking to the literal sky's been an extended metaphor for the character in the past.
What it becomes in English we'd just have to wait for.
It's not the same word with two meanings, it's how its written making two different meanings.