User blog comment:CoyoteDork/Season 6 New Series Regulars (Speculation)/@comment-8718836-20160117173951

It could be anybody. They promoted Missandei last season and she is really not that important.

With that being said, I reckon we'll see at least one or two of these people be promoted to main cast.
 * Grey Worm
 * High Sparrow
 * Doran Martell
 * Olenna Tyrell
 * Osha