It would seem that some re-arrangment of current IJN tech tree is incoming, in addition to a new mini-tree that goes only to tier 8.
Tier changes:
Kagero, Tier 9 to tier 8
Fubuki, Tier 8 to tier 6
Hatsuharu, Tier 7 to tier 6 (New Tree)
Mutsuki, Tier 6 to tier 5 (New Tree)
This re-arrangement features 4 new ships in total.
Akatsuki at tier 7
Shiratsuyu at tier 7
Akizuki at tier 8
Yugumo at tier 9.
Provided pictures:
Akatsuki:
http://worldofwarships-asia.gcdn.co/dcont/fb/image/7550f276-7348-11e6-8575-38eaa7374f3c.jpg
Shiratsuyu:
http://worldofwarships-asia.gcdn.co/dcont/fb/image/7c8a6d74-7348-11e6-9f14-38eaa7374f3c.jpg
http://worldofwarships-asia.gcdn.co/dcont/fb/image/7e52e2bc-7348-11e6-9f14-38eaa7374f3c.jpg
Akizuki:
http://worldofwarships-asia.gcdn.co/dcont/fb/image/79133f86-7348-11e6-8e87-38eaa7374f3c.jpg
http://worldofwarships-asia.gcdn.co/dcont/fb/image/7766d4a4-7348-11e6-8e87-38eaa7374f3c.jpg
Yugumo:
http://worldofwarships-asia.gcdn.co/dcont/fb/image/801e81aa-7348-11e6-9dc7-38eaa7374f3c.jpg
http://worldofwarships-asia.gcdn.co/dcont/fb/image/8206d0b2-7348-11e6-9dc7-38eaa7374f3c.jpg
