Either they didn't know or wanted to do it better? I can see it's got some different wording and the scans are better- or at least seem a bit cleaner/crisper imo.
I really like it tho so not complaining - i'll reread it happily :)
I can't speak for everyone involved but when I was proofreading/qcing it I just wrote off the sense of familiarity as it being another similar oneshot I'd read. And considering that the title was translated differently it's quite possible that the older version got overlooked.
This scan is definitely crisper than the previous one; that's the biggest improvement. I also like the translation slightly more, though the differences are admittedly fairly minor.