oh man i personally was too busy being swept away with the excitement of having a new unit being announced in real time to really pay attention to what's around me (i even drew a little doodle of the two out of excitement). i felt sad about it later upon realizing what it meant for mam the unit, but i was just happy to see madara have some sort of cool thing going on for him

i only experienced the english fandom, but it was definitely negative; i was a fledgling in the fandom, and the little people i followed were all deeply negative about it to the point i think negativity really got to my heart for the first time and i had to mute people. mamPs were definitely upset, but there was a lot of bitterness towards kohaku too; "why is a new character nobody cares about being given a special unit situation?" that sort of thing!

the new units were still having their story told with the final installment of the main story being released only a couple months earlier, with very little people having read it due to there being no translation for such a massive story. people were still lukewarm towards a lot of the new characters, so the english fandom largely didn't feel all too stoked about kohaku, and double face by extension. those who didn't care didn't know how to feel about this new character being in two units yet, and those who did care were confused why kohaku was being distanced from crazy:b.

their jazzy spy movie style of music was very unique and fresh though for the franchise though, i remember there being a lot of people talking about that! there was a lot of people impressed by =EYE= and the mv despite their feelings towards the unit. that's about all i can recall though, from my limited experience.