Hmm...I guess that's that! Maybe I wasn't watching that intently. Thanks for the info!!
You have to go back to second season for that information. The fact is Michonne told Rick that is the way how she does it. None of us really knew that she was also participant to Andrea's death. Shame on her. She should have acted, but when she Ricktator questioned about her, she told, "If you remove their jaw and arms, they become pacified."
In a way it was a prototype Whisperer, except she never whispered or acted like them. Instead she was always, and will always be a human. Life comes first. But we all know that her true love after the fall became Rick.
I suppose we'll be left to speculate about what appeared to be an army marching off toward the horizon. "Helicopter People"?
That's what I thought as well. You look at the above screenshot of the map, and you'll see that the whole place was a Naval Research Facility, and they were doing animal experiments in there. None of the scientists said that they were studying the dead. They said that they came there and it was like that, abandoned and in a state of ruins. Except the one place, the research facility where Virgil locked his family.
The whole place smelled like a place that the helicopter people would have used and then abandoned to do something else. We cannot know if the squadrons of men, and horses at the end are their people. In terms they are like Henrik's people at the Exopolis in trilogy. They went hiding and they used government stored items to be the Authorities destined to rebuild the world, when the time comes.
We still don't know what A and B classification means, but I can suspect it has something to do with the people and their skills. Ricktator was a survivor. He was a lawman, a leader and a builder. He was also an Alpha male. So, if that makes him the A list candidate, the B people must mean special skills. Something that the Helicopter people couldn't accept losing, because the value of those skills/knowledge.
It's just at the end of the world, skills and knowledge doesn't come easily. You have to be somewhat extraordinary to survive in the Kirkman's world. The normal just doesn't cut it in the long run. The average gets buried or turned. The weak has no chance. But as Mother Nature is a bitch, it's kind of funny that the weaknesses are balanced other ways. Think about for example Hawkins.
He was weak but also super smart. In the Kirkman's world he could not have survived.
In reality when Michonne lost her kids, she kind of lost her will to live as it happened to many others. It was Rick's group that gave her the will to live and a reason to see another day.
I think it was a brilliant move from the writers to show the audience another way of how things could have gone down through Michonne's trip. It was the boots that finally broke her down and then she didn't care about anything other than finding Rick alive.
Who knows maybe they'll bring Rick back one day. Maybe we'll even get to see the research station again in the movies. It's just I suspect Rick also might appear in the series again.