Kazuya was indeed killed by members of the Coven in this incarnation too, and there might very well have been an attack on the Barracks as well. Most of the storylines might still work, they just need to be properly unearthed first as the Coven has not yet fully revealed itself for what it is.
The precise circumstances around Kazuya’s death though would probably be an assassination carried out by extremists loyal to the Coven’s cause. From my perspective, the Coven has been around for a while now, but its been biding its time and mostly kept to a very small circle of perhaps two to three individuals which are slowly laying the foundation of the Organization as a whole.
Hotaru might very well be one of these people, a mole within the Gotei 13, other such individuals would probably include Hikari Maebure and possibly Shijin assuming we still use him.
Here’s how I envision this storywise.
- Kazuya is killed in a manner very similar to what happened in Dawn of the Coven in an attack on the 9th Division Barracks. Sajin returns some time after and takes over after him.
- After several years of leading the 9th Division and possibly tutoring Hisagi in what it means to be a Captain, Sajin transfers to his current Division in order to allow Shuuhei to succeed him as the Captain of the Ninth.