When it comes to the world of The Walking Dead no one knows when the time will come for a character & actor to depart the series. Usually, the way they leave is their characters meeting a sad or grisly ending.
Very soon though they might lose one to another reason.
As was rumored/reported earlier this month, Lauren Cohan’s contract for season nine still remains unsigned as her and AMC have not reached an agreement, as she reportedly is asking for equal pay to Andrew Lincoln & Norman Reedus, but now according to Variety she has officially signed on to ABC’s drama pilot Whiskey Cavalier.
A pilot, of course, will not nessicarily be greenlit into a full series, but picking up a new job seems to leave it a very real possibility that the actress has brought her time in the zombie apocalypse to an end. There is still a chance that the filming schedule for both will still work out and Cohan could return to the series in a recurring if not regular role.
Generally though securing potential new work has meant an actor is slated to leave the series soon, much like Chad L. Coleman and Sonequa Martin in previous seasons who picked up work on other genre shows.
Unlike most other shows though, if Cohan does choose to leave, how the series will handle a major character just being gone is an interesting question. There is no moving to another city or joining another hospital/precinct as you do on most other drama shows as the world is over.
Killing her character off screen would not bode well with audiences, meaning the series would likely have to either come up with some reason or work out a way to have her come back just enough to write her character off in some way.
As of now, this is all speculation of course because a contract very well could be signed soon for her return to the show.