No no, it's like how the royalty do. When you're that far up the high-class social status, you remain in your mansion/manor/castle/temple/submarine/whatever. Have you ever seen Princess Diaries, or What a Girl Wants? Or The Prince and Me? It's like that. They remain with their families. (What a Girl Wants is better though, because they're more close to the Fowl status)
I've seen the Princess Diaries, but not the other two, so I have no idea what the comparison is.
But it just seems weird. I guess I see what you're saying though. That just makes it all the more better for having his parents die though, so he's not stuck living with them forever. That's really harsh though. Also, then he would have to take care of the twins, and that's just not Artemis.
Maybe he could keep the manor and kick his parents out? I don't know.