Negan is amazing and I've heard that the tv show is pretty much following the same plot, so he should show up in the next couple of seasons. And I think the tv show needs him, because it just missing that main bad guy like it had with the governor.
And I think The Whisperers is only about 4 or 5 eps in. And it's worth reading, the way time has passed and all the characters are just in a different place, I guess it highlights that survival isn;t some goal to be reached, it's a constant struggle.
Also I kinda hope that new stories are told, I would love a spinoff comic like they're doing for the tv show.