they just showed off the reveal trailer of the boss, they never showed gear that day. where are you even getting this info from? even with recent datamine no ones found this stuff
Like other people have mentioned i expect at worst case just a ssa slot addition or at best case some extra stats on top.
With final episode boss around the corner logic says that whatever units drops from there should be top tier by default,unless they want to keep the new stuff from boss as drop only for some reason i will hope that they learned their lesson and the gear will be obtainable in other non luck involving ways.
I'm expecting only 10-20 more hp, 20-30 more def, pp stays the same, maybe 20 more atk.