The problem was black blades being used as a feat to put the wielder above any non black blade user by default, with people putting Mihawk above even prime Whitebeard and Roger.
Sure, but that was always delusional to begin with. Mihawk was not even on par with Old but sane WB, let alone prime WB who was ~ Roger.
Sooner or later that would come to pass.
Aramaki having a black blade would probably just make a black blade more of an armament feat, which would also be a contrast to Fujitora, with Fujitora having honed his CoO to perfection, while Aramaki did the same with armament. But you won't need god level ACoC to forge a black blade.
Overall I agree, I have always had that split (Fuji - God level CoO; Aramaki - God level CoA) in mind. Probably there Is something more, maybe CoC too and maybe CoO too, but clearly, I agree, It wouldn't be (and never was) a strict CoC feat. If It was, Shanks or Roger would have had one.
Still, we are talking of the last hurdle a powerhouse like EoS Zoro is going to have and something even the overhyped Oden failed to achieve.
The sole fact Aramaki managed to forge one, if he has one, put him above Oden as a swordsman, let alone if we add the fruit. And some people don't have Admirals above Oden, let alone fruitless. This would be huge thing.