For those who may be confused as to why she has two new forms, this one with the wooden flight deck is her actual Kai Ni. The other one with the black flight deck and extra armor is her Kai Ni Kou (aka Kai Ni A), her alternate Armored Carrier form.
The best thing is that she can switch to Kai Ni Kou from Kai Ni and then back again at will, though with a small resource cost and modernization reset.
For those who may be confused as to why she has two new forms, this one with the wooden flight deck is her actual Kai Ni. The other one with the black flight deck and extra armor is her Kai Ni Kou (aka Kai Ni A), her alternate Armored Carrier form.
And from what I can translate from the tweets, the other form has less plane slots, and possibly she will be able to carry jets in the future.