I feel like the comic is hitting a major crossroads and had an idea of how the rest of the series might pan out. Of course I have no clue, and I also don't keep up with possible future spoilers so this is all speculation:
With the supposed inevitable demise of Andrea and the Saviors (strangely placed) ill will towards a damaged Alexandria, and a destroyed Hilltop.. our group is extremely vulnerable and it seems like we might be seeing a "Changing of the guard".
Here are some things that I think could happen that keep this series moving forward while staying interesting
1: Andrea dies.
2: Negan takes back control of the Saviors and publicly executes Rick (perhaps Carl and a handful of people witness this as well.). Why would Negan do this now, after having so many chances to in private? Well in my eyes he wouldn't just kill Rick for his own personal gain. He'd do it to make a statement to his people and to the world. A statement that he's back, he's in control, and he took out Rick Grimes.
3: Carl, Michonne, Magda and her group, Maggie, Eugene, Jesus, and a few others retreat to the kingdom. Negan takes the fight to an undermanned Kingdom and the Kingdom falls as well.
4: They hit the road to Ohio with Eugene as it's their only / best option.
5: Carl grows into a leader. During this time perhaps they encounter the whispers and finally finish them off.
6: They plan to take out Negan and seize control of Alexandria, Sanctuary, and the Kingdom. They succeed and the Series ends.
The reason I thought of this is that I've been thinking lately about Andreas death and though I'm sad about the thought of her biting the dust, I also realized that it's not earth shattering anymore. The only earth shattering thing left for this series to do to really invigorate itself again is for Rick to die.
It can't be Carl because really this series has always been about keeping Carl alive. I think the best payoff is to know that Rick kept Carl alive and showed him how life COULD be. He helped shape Carl into a strong, kind, brave man that will end up being a great leader of this new world that Rick envisioned.
We've known that Rick has never made the smartest decisions, and honestly keeping Negan of all people alive probably isn't a good decision. There's a reason capital punishment exists (and even moreso reason for it to exist in a world like that, where you house your criminals in a basement) and bottom line Negan was and is too big a threat to have been left unchecked.
I think part of the reason Rick has kept Negan alive in the first place is because it was a more vindictive fuck you to Negan than a "justice" type thing, no matter what he says.
"You're going to rot in jail until you die an old man Negan. You're fucked."
One of Ricks greatest personal victories and honestly in my eyes the bravado that kills him in the end.