No, it wasn't Billboard or anyone else that christened Michael Jackson the King of Pop.
Despite spin to the contrary after his death, according to MTV that "King of Pop" nickname was always from Michael Jackson himself.
Here, in all it's glory, is the origin of nickname - The King of Pop.
From I Want My MTV: The Uncensored Story of the Music Video Revolution © Dutton 2011
'til Kings are crowned
Keep the Adventure Alive,