As this thread morphed into a general-patch discussion, will be putting original 0.3.1 OP under spoilers.
From: http://blog.worldofwarships.ru/0-3-1-byulleten-razrabotki/
IJN CVs, Hosho, Zuiho, Ryujo, Hiryu, Zuikaku, Taiho and Hakuryu.
AND
USN BBs, which will include Michigan, Arkansas, New York, New Mexico, Colorado, North Carolina, Iowa and Montana.
High-level cruisers. As an experiment Ibuki, Senjo, Baltimore and Des Moines get activated ability "Rehabilitation work", which was previously available only battleships.
Kitakami - wonder