I can't see Mojo or Juggernaut who is now Cytorraks slave a horseman. And like I said it's Leah Williams she's writing a love letter to Emma.
It may just be the 80th anniversary thing
And the best fit would be:
Magneto - War
Mojo - Famine
Mystique - Pestilence
Juggernaut - Death
Same it's doubtful she will theres 5 of them and only 4 horseman spots. And Juggernaut is too dumb to be part of a Cabal. Probably some stand a lone 80th anniversary thing
Also Claremont doesn't play nice with others I imagine he'll just ignore all Magneto continuity and finish where he left off
Miss Sinister, Bastion, Havok, Dazzler, Beast, Warpath and Banshee, Donald Pierce are all in Astonishing X-Men. It really made sense for Emma to be in that book. She has ties to all. But they definitely look like they're stalling