It took some Googling, but I was eventually reminded that the camps depicted this issue -- with Ahab as lord and Rachel as hound -- were a result of the assassination of Senator Robert Kelly and the ensuing passage of the Mutant Registration Act, as depicted in the classic "X-Men: Days of Future Past." Kelly is saved in that timeline, but later assassinated in the "X-Cutioner's Song" event; the Mutant Registration Act eventually becomes the Superhuman Registration Act explored in the "Civil War" event. As such, it would've been unclear what circumstances would bring about the creation of the camps in the existing timeline; Remender essentially steps into that gap here. We learn that the Red Skull eventually uses Charles Xavier's powers to take control over the Scarlet Witch. Armed with their powers and revealing certain secrets about mutant "crimes" that incite the human population, the Red Skull creates the world of the camps.
However, I'm less clear on the events at the end of this issue. At this point, the Apocalypse Twins appear to be fulfilling Kang's wishes, leading mutantkind on an exodus from Earth. I assume that it's to make it easier for Kang to conquer Earth, though Remender hasn't explicitly said that. The Twins have hinted that they're implementing Kang's plan under his supervision, but that they've planned a twist, though we don't what that twist is yet. Based on this issue, it appears to be the theft of Jarnbjorn, given the Scarlet Centurion's panic over its disappearance and its apparent link to the disintegration of Kang's empire around him. In fact, in issue #8, the Twins did directly tie Jarnbjorn to undoing Kang's "crime," though we also don't know what that crime is yet. However, as far as I'm aware, the only thing that the Twins have done with the axe is murder the Celestial, something that sounded like it was all part of Kang's plan in issue #7. If it was, then they obviously use Jarnbjorn for something else, though we haven't yet seen it. If it wasn't, then why does the murder of the Celestial lead to undoing Kang's "crime?" (In fact, I almost wonder if the Twins murdering the Celestial on Kang's behalf isn't the crime. If so, what do they do with Jarnbjorn to undo it?)
I get the sense that we're close to the big reveal, but I do find myself hoping that it comes somewhat soon. I'm still enjoying this storyline thoroughly; it's just getting harder to keep all the details straight after this many months.