I take it that /a/nons got impatient, which is odd because I never got the impression that Abyss When Scans (which is solely dedicated to this manga) has ever particularly lagged behind official release.
In which case, there must be some /a/nons that are all the way on this train, which is interesting to think about. Maybe they have a plug that can somehow manage earlier raw acquisition?
EDIT: I just realized they released two chapters in the same day, so I guess the primary scanlation group was behind, after all.