I think if anything it just patches up the story by actually saying that the Jona guy and Sumire are infernals; Jona was hinted at being an infernal but the concept of doppelgangers wasn't really a sure thing when those hints were dropped.An exposition chapter is fine but we really didn't learn anything meaningful this time around, beside the fact that the freak was the creator of course but him being most likely the most unpopular character in the series makes a very mild "ooh..." reaction, because we knew he wasn't human and that they made the church and the Amaterasu, we knew the nun was making the earthquakes too ... So all we get to see is the introduction to new elite forces.
It's ok for a transition chapter.