I found this link on the Pyramid Vault. I have no idea what "The Book of Day and Night" is, and I have no idea how true these rumors are, but I'll leave it to you to judge:
A sneak peek from The Book of Day and Night

Reading through the thread, it's clear to me those aren't upcoming rules/fluff, but rather home-made material accompanying your standard "Cathayan/Arabian/other overly stereotyped wad of rubbish list" project. No connection to the Design Studio whatsoever.

I haven't read that thread, but I can tell you that "thereisnosaurus" (the poster) is in charge of a Cathay project. They've been working on it for a couple of years, I believe, and have just started playtesting recently. They're really going to town on it.

Personally, I like the fluff for the Shigaion, but I think their rules are way too similar to those of the Strigoi.

isnt the GW development team responsible for all new updates to the game? at least the official ones.