I hope you meant Volunteer humans, and not Sacrifical humans because that sounds more like Orochimaru than SO6P.
In any case, I would think/say that the way the Beasts speak about humans, that does sound very much like they have always been separate and different from humanity, to my eyes at least.
I am not perfect and I defy you to prove otherwise
Growing Old Gracefully is an Oxymoron ... Mostly Moron !
I always believed that the Bijuu adapted, in someways, the personality of their hosts/people that controlled them and the ones they met, for example, Kurama being abused by a human with the greatest amount of hatred at his time (Madara), has become the most hateful bijuu of all (well, maybe beside Jyubi ;p). It's possible that the wicked monk, was Shukaku's first host which he (the bijuu) liked very much (?), would explain why they knew it's name.
I have seen people coming up with bijuu's names, but I haven't seen anyone (?) predicting the 10-tails name, I wonder if it ever had one, because if it was the first being, then there wouldn't be anyone to name it, right ? Thus in a way, the 10-tails could be similar to Tobi, who is a Nobody and perhaps doesn't have a real name as well ?
What do you think the fate of the Bijuu will be post War?
My feeling is in he future Bijuu will be respected the way Giant sum moned animals are and only sealed in people when they give consent. I had an idea Konohamru might become the 4 tails(Son Goku) host in the future as it would fit the monkey theme of the Sarutobi clan and give him the ability to compete with Naruto.
it's way cooler this way anyways, and by far more convenient.