I am not surprised at all that Andrew Lincoln is leaving TWD. I’ve said it for years (as did others), but Rick’s entire character revolves around CARL. We always said Carl would be safe because if Carl died, then Rick’s character serves no purpose and has no purpose. So the moment they killed his ONLY reason to exist in the show, I knew Rick was next. Andy even said it:

I love Richonne and I know Rick loves Michonne and Judith, but they’re not Rick’s reason to exist—Carl was.

“It is being reported that Lincoln will be exiting the AMC series in its ninth season, currently in production, which ComicBook.com can confirm from multiple independent sources. ComicBook.com can exclusively report that AMC is expected to announce officially Lincoln’s exit from the zombie drama ahead of his final episodes.
Furthermore, several other cast members are in their final contracted years, though their fate with the AMC series is up in the air. Among them is Danai Gurira, who has played Michonne since the show’s third season. Lauren Cohan is also expected to exit the AMC series as her current contract for Season Nine only brings her back for six total episodes.
How Lincoln exits the series in unknown but it is expected to be gone before Season Nine’s finale.” - comicbook.com