Season 9 cast updates

Here's every known casting update for the moment:

Brett Butler will arrive as a "salt-of-the-earth" type named Tammy Rose, and John Finn will portray her husband Earl who also happens to be a blacksmith.
Rhys Coiro and Zach McGowan will appear as Jed and Justin, respectively, two characters that are each uncooperative Saviors.
Dan Fogler will portray Luke, a survivor who is apparently keen on making friends for the sake of safety.
Nadia Hilker has been cast as Magna, a character from the comic. Magna is a tough as nails survivor who has been living on the road.
Samantha Morton joins the cast as Alpha, leader of the Whisperers, one of the most iconic villains from the comic books .
Eleanor Matsuura joins cast as Yumiko.
Lauren Ridloff will be joining the show for a multi-episode arc as Connie, a seasoned survivor deft at using her senses to read people, situations, and trouble. Her character is deaf and uses American Sign Language (ASL) to communicate.

Sources below:

https://www.tvguide.com/news/the-walking-dead-season-9-alpha-samantha-morton/

https://www.thewrap.com/the-walking-dead-casts-nadia-hilker-as-magna-exclusive/

https://www.hollywoodreporter.com/live-feed/walking-dead-samantha-morton-play-alpha-season-9-1128840

https://ew.com/tv/2018/07/19/the-walking-dead-season-9-dan-fogler/

https://comicbook.com/thewalkingdead/2018/07/16/the-walking-dead-yumiko-eleanor-matsuura-cast/

https://ew.com/tv/2018/07/16/walking-dead-lauren-ridloff-season-9/