I don't have time tonight to read all this, so pardon me if I'm being redundant, but:
It's most likely more than a phase. People change personas COMPLETELY in High School, very rarely does anyone come out the other side of High School anything like they were when they went in. I had a friend who went from an innocent, shy, girly girl (shopping, shoes, pink, boy bands, etc.) to a psychotically emo crackfiend. Not saying everyone changes as drastically as that, but it is perfectly normal to alter your interests and priorities in High School.
It's most likely more than a phase. People change personas COMPLETELY in High School, very rarely does anyone come out the other side of High School anything like they were when they went in. I had a friend who went from an innocent, shy, girly girl (shopping, shoes, pink, boy bands, etc.) to a psychotically emo crackfiend. Not saying everyone changes as drastically as that, but it is perfectly normal to alter your interests and priorities in High School.