I signed up with a nickname email when I was younger. For example teenager@mac.com. You can later make an alias like John@mac.com. But every time you sign into iCloud, or write a new email on your phone, it's gonna default to teenager@mac.com.

It is a really bad issue for people that use apple's mac email exclusively.

And I can sympathize with the article. If you're divorced, and you change your name, you have to sign into iCloud with your ex husbands name every time you sign in or send a default email. You can't change it.