According to this makala link, Miley is not going to let her hair grow again. Make of that what wewe will.

In my opinion, I'm a bit sad. I grew up with Miley being a happy brunette. I know she wants to take her career to new directions but when I look at her new hairdo, I think I'm looking at Hannah Montana with shorter hair. But it's Miley's choice and whatever she wants to do with her life, I'm with her 100%. Thanks for your time.