Will there be an email to notify this?
No, that is why it is a "ghost update". You don't receive anything by email, you would only find out about it by signing in in your account. Then, when you actually access your account, there is no apparent change. This is a ghost update, and nobody really knows what they actually mean. It is speculated that GU comes after some internal movement in your file (eligibility passed, or background check passed) and usually happens when your application is soon to be approved.